with other households and doors to just christmas day itself and imposes a stricter travel ban between itself and the rest of the uk. now on bbc news, amanda ruggeri explores the new technology that is allowing archaeologists to explore the hundreds of mayan structures that are still hidden beneath the amazon. located in northern guatemala, the mayan biosphere reserve is the largest rain forest north of the amazon and one of the world's most important hotspots for biodiversity. it also was once the heart of the maya civilisation. today, hundreds of houses, fortifications, temples and other structures lie hidden beneath the jungle. i like this part. but some archaeologists are determined to change that. they've devoted their careers to getting the jungle to give up its secrets, and new technology has revealed that, despite decades of work, they have only begun to scratch the surface. there's a deep hole, and that's where they're digging right now. don't let me down. this maya city has been an obsession of archaeologist francisco estrada belli's for the last 20 years. he calls it the gift that keeps on giving. let's try not to get stuck. yeah. in recent years, his work has been aided by the use of lidar, a technology currently transforming archaeology. i've come here, on the border with belize, to learn more about what estrada belli has discovered. this was one of the most populous places on earth a thousand years ago, if you think about it. we're already estimating eight to 11 million people in an area of 9000 km2. yet they were using very sustainable practices so they could do this for 2000 years. so, you started excavating... ..more than 2000. that was my first season, yeah. it was very adventurous. we worked for two weeks, and then it started raining. we didn't have any cars and the roads were all flooded, so we got on out on horses. the city of holmul dates back to 800 bc. it was abandoned 1700 years later. one of its mysteries that estrada belli has been trying to solve — its empty tomb. i think i know why they abandoned it, because the date of the building matches with a guy who was supposed to be from here, being sacrificed, year 748. after that, pretty much all monumental construction stopped here. so, tell me what that would have meant. so, tikal was defeating its archenemy, the snake kingdom, and they already defeated the actual snake kings. now they were going after its former ally. this is historical archaeology. we don'tjust talk about processes any more and theories, we talk about specific events, specific people. we need a description. and yet, this tomb was almost destroyed before estrada belli, or another archaeologist, we re belli, or another archaeologist, were able to discover it. here is the tomb chamber. while. looters came and dug a hole behind this doorway. and they missed by 27 metres, actually. that's an image of one of the dead kings. you can imagine what they would have done. they would just blast through it. it is all there and it goes for eight metres that way and another five this way. it's been damaged on purpose by the ancient mya. nothing else, really, is damaged. the mya believed everyone had a soul, including images. when they we re soul, including images. when they were burying someone, they would let the soul out by killing the image —— the soul out by killing the image —— the maya. that's the god of the underworld. he's holding a hieroglyphic. two syllables. two words, really. 0ne means the first, and one means the food. so he is holding the first of it and offering it. that's the i? he's got blue under the eyes. he's tired. laughter he's been up all night. he's one of the snaking ‘s. he's been up all night. he's one of the snaking 's. what did you feel in that moment when you realise that? when i saw it, i thought my career just made a big jump. jackpot! estrada belli was lucky to find this. thejungle estrada belli was lucky to find this. the jungle doesn't make for a specially easy archaeology. 100 yea rs specially easy archaeology. 100 years ago, and archaeologist from harvard first came to holmul and discovered these temples, but he missed the oldest carving which dates all the way back to 350 bc. the archaeologist died shortly after working here. by a serious of diseases he contracted. —— a series of diseases. he returned with a massive store on his nose which never healed. he neverfinished his reports when he died. it was actually published by one of his friends at harvard. they forgot to mention this tunnel, and they had found the window. so, we kept digging and there is this massive carving explaining what the temple is all about. are these beetles still around? yes. it's called the assassin bugs. i'm glad we are going in now. welcome to the underworld. you made a sound. turn the light on. watch your step. we're going to walk around the exterior and go to the front. and this is the front of the building. whoa! it's a lot bigger than i was expecting. yeah, it's all perfectly preserved. for 21100 years. what you have is a massive head of the monster with the mouth open. here inside the mouth of this monster is the face of an old man. it has the same wrinkles, but the teeth like that. it's the image of the god of the underworld. it's not going to change. jungle creatures and diseases are just two of the problems that archaeologists have had to face. but historically, the bigger threats to the rain forest and its archaeology have been rubbing and looting. this is of the devil. we don't know why they choose that name. it's an early classic building, between 300 a.d. to 680. wow. we're going to try to see the earliest version of this building. what was it use force? -- used for. killing and the sort. this devil temple was allegedly named because of the sides... more fitting is that it's king who ruled in the fourth century a.d. was buried with the remains of six sacrificed children. that's where we found the tomb, two metres away. so i'm standing on top ofa metres away. so i'm standing on top of a king's tomb? yes, from 380 80. but no one is in their any more? no, we moved it. we found it, the chamber was completely sealed. we still felt the cold breeze and the smell, like something was put into a process. when we found the first king, u nfortu nately, looters ca n when we found the first king, unfortunately, looters can come in. they're unfortunately, looters can come in. they‘ re really well unfortunately, looters can come in. they're really well organised and can take everything. 0ne they're really well organised and can take everything. one day we hired a group to protect it, but it didn't work because some of them tried too. i confirmed one of them took his gun shot. at the time, i think i was a good liar. i thought this is a computer. we are filming everything. that's when it stopped. another major challenge for the maya biosphere reserve is illegal logging. when the jungle biosphere reserve is illegal logging. when thejungle is clear. it doesn't just affect the animals in the rain forest, but also the sites, which are often irretrievably damaged. loop to the sites where the marijuana was growing and then collected to harvest. several illegal activities are still going on in guatemala. illegal lock being, which is not a problem here specifically, but in other regions —— illegal logging. drug trafficking. we're fortunate here. airstrip from columbia, to go across from mexico and there from the us. they burnt all the forest. this area has done much better because it was given concession for sustainable logging. in the last 20 years, the local communities have stopped the drug trafficking, the land invasions, the dufour station, and that's why sites like that are recovered by force —— the deforestation. we think what we have in place here works much better because the local communities are empowered and have an incentive to protect the forest. for as long as i can continue, they will protect the forest. this man is vice president of dr bulverde concession which has been given to local residents for sustainable logging. while it turns out that concessions like these can have quite the opposite effect. by being run with strict adherence to sustainable management principles —— arbol verde committee. community concessions like this one have actually predicted the reserve. 0ne one of the biggest challenges to archaeologists in the maya biosphere reserve isn't logging or even looting. it's a fact that it's extremely difficult to find or identify structures in a jungle stick and wild as this one. and that's where a technology that's relatively new to archaeology, lidar, has been transformative. so, this hill is supposedly a pyramid. they think it might be may be as big as the great pyramid, it's definitely steep. it looks like a hill. so, it's pretty amazing that they're able to find that out through lidar. we're right here. 0nly10% of t paul has actually been excavated and discovered —— of tikal. this feels very indiana jones. lidar is a type of remote sensing technology that's used to create extraordinarily detailed 3d maps and representations. in the reserve, lidar is being employed in two ways, from air plastic to create topological mass and to room hand—held scanners to build better 3d models of a particular site —— aircraft. —— technological maps. the process of beaming lasers from aircraft, is the initiative of the foundation for mayan cultural and natural heritage. it's amazing. it's massive. this is one of the bigger temples of tikal. what is lidar exactly? what makes it such a great tool? it really strips off the fore st tool? it really strips off the forest canopy with billions of laser beings that met individually —— laser beams. that will give tremendous use for the rain forests and the biomass. and you said billions of laser beams. how many billions of laser beams. how many billions of laser beams?” billions of laser beams. how many billions of laser beams? i think our first data said 60 billion returns. so, it's an incredible amount of data. how long did it take to collect that? only a couple of weeks. we were something like eight flights. 2100 km2 of area is covered in that amount of time. you obviously have a great appreciation for understanding how sophisticated the mayans were. but did the lidar increase that understanding? yes, the lidar showed without any doubt that we totally underestimated their engineering capabilities in terms of landscape, modifications to make the landscape, modifications to make the land for sustainable to irrigation, bringing water to places to cultivate, to stop erosion. it split a mind blowing. that's how! cultivate, to stop erosion. it split a mind blowing. that's how i felt. —— it's pretty mind blowing.|j thought they were sophisticated already, but not at the scale. one of the sites where lidar has been especially helpful is here. lidar is the first step. it shows us everything. it gives us the footprint, but then archaeologists have to check it. lidar makes it so that as archaeologists, we don't have to spend all her time figuring out what's there and instead, we can focus in on addressing questions we wa nt focus in on addressing questions we want to. so much of our time is spent mapping and just trying to find places, and lidar showed us we weren't very good at it. a lot of sites around here were abandoned at the end of what we call the classic period. around 900 something like that. l's oats had people living here up till the 1300s. we're probably somewhere near the new spain road that passed down through central america and supposedly was built on top of a major pre—columbian three way. but no one has actually pinpointed where that ran through. we wonder will lighter eventually reveal that for us —— will lidar. that will be amazing. the first king was such an important character that a temple was created for him so he would never be forgotten. when you are here, be careful. if you fall... so, don't fall on the sculpture. this was all from one king? yes. this king not only was powerful. we know about his extension of power. lidar is helping us extension of power. lidar is helping us recognise everything this king did to preserve him, his family and his legacy. the creation of a dynasty. i find like this tell you there is a king, then the lidar helps you realise what the whole context is. everything they built, we can make more sense of it. you have been coming here for 20 years and knew the area of very well, but you still hunt and suspected that this was a major —— but still wouldn't have suspected. when you see it in the context of any more —— of lidar, it makes more sense. my job is typically two things. i think it was a 100 metre long wall, i had no idea continued for several kilometres. when you got that diet backed and started to see all that, what'd you say —— all that data.|j was like oh my god, my god for hours. 0h was like oh my god, my god for hours. oh my god, look at this? 0h my god, look at that! you think you know what you're doing, and this thing is so much better. we can do what we do in 20 years into days. same work and it's better —— in two days. the lidar shows how big the rain forest is and how many trees there are with much a greater precision. hello there. the heavy rain we've seen over recent days has been working into our river with the rivers running high. we've seen a number of flood warnings over the last 2a hours. some pretty high waters here. 0n the satellite picture, a number of showers are waiting to come in on sunday, wrapped around this area of low pressure. further afield, further areas of low pressure queuing up waiting to bring more rain. it's going to be a windier day across northern ireland and western scotland, quite blustery for most of us. showers easing off for a time, but a cooler day nationwide. looking at temperatures between 8—11 c. for monday, looking at the next area of low pressure moving on pretty quickly. this is going to be bringing in widespread and heavy outbreaks of rain across england and wales with strengthening winds, particularly affecting the south coast and into southeast england for a time. rain from the north and scotla nd a time. rain from the north and scotland pushing eastwards with time and the weather slowly brightening up and the weather slowly brightening up from the west as we head into monday afternoon. still mild across southern areas, temperatures could reach around 13 degrees in london but across northern areas, it's going to be getting colder with temperatures dropping around six celsius the afternoon. tuesday, we see this weatherfront lurking across southern counties into england as a southern counties into england as a southern wales, the midlands and east anglia. with that will probably come a lot of cloud. mist and fog patches are possible and as well as that, more rain to come across the southern areas that, more rain to come across the southern areas as that, more rain to come across the southern areas as well. further north, a few showers for the far north, a few showers for the far north of scotland. still chilly across northern areas of the uk, milderair hanging on across northern areas of the uk, milder air hanging on a cross the far south of england. into wednesday, low pressure. this is going to bring outbreaks of rain, but some uncertainty about exactly how far north this band of rain gets. it could reach as far north as scotland. another area of uncertainty as we don't knowjust yet how intense the area of low pressure is going to be. that will affect how strong the winds are going to get. but i think at the moment, for england and wales, rain at time. scotland and northern ireland, probably north england, more likely to see sunshine, cold weather and scattered showers. the uncertainty for wednesday clears through thursday and friday as colder air actually moves in across the whole of the country. a real change in weather fortunes as we head into christmas eve. a fairly wide for its across northern areas —— widespread fraud. the few showers affecting northern and eastern coast of scotla nd affecting northern and eastern coast of scotland —— widespread frost. highs of 11—6. of scotland —— widespread frost. highs 01:1!“6 . there will be a start and widespread frost. frosty as we head into christmas day but there should be a lot of dry weather and sunshine for most areas. cloud will tend to fill in across the north and west of scotland as we go to the day with a south—westerly when picking up. highs of around nine celsius. 0therwise, christmas day looks like being a cold one. five or six celsius if you can get outside for a socially distanced walk. should be fairly decent weather for that. cloud will tend to build over the weekend. eventually some rain pouring out from the northwest to sunday. that's your weather. nearly 18 million people in london and south east england to move into stricter tier for restrictions from midnight. people must stay—at—home and nonessential shops have to close. for those in tier 4 it means the relaxation of rules that christmas has been scrapped and reduced to one day, the 25th, for the rest of england. we must be realistic. we are sacrificing the chance to see our loved ones this christmas so we have a better chance of protecting their lives, so that we can see them at future christmases. the new restrictions are due to a spike in cases that is being blamed ona spike in cases that is being blamed on a fast spreading new variants of the disease. the whole of wales is to