hello and welcome to switzerland. i m in the town of chateau d oex. it is known for its gruyere cheese, which is delicious, and the international balloon festival, held in the valley behind me every winter. but let s start somewhere a little warmer. mexico city s ancient canal network was first built by the aztecs. it stretches 180 kilometres and these days the whole district of xochimilco is a unesco world heritage site but one that could do with a bit of a clean up. we sent eva zu beck there to find out why. check out all these amazing boats, they re so colourful. these are called trajineras. i was honestly expecting to go
hello and welcome to switzerland. i m in the town of chateau d oex. it is known for its gruyere cheese, which is delicious, and the international balloon festival, held in the valley behind me every winter. but let s start somewhere a little warmer. mexico city s ancient canal network was first built by the aztecs. it stretches 180 kilometres and these days the whole district of xochimilco is a unesco world heritage site but one that could do with a bit of a clean up. we sent eva zu beck there to find out why. check out all these amazing boats, they re so colourful. these are called trajineras.