has been exploring underground berlin for 2 decades he co-founded the veldt in association in 1997. around 8 meters below the surface of the news team have spent he is clearing tens of thousands of cubic meters of rubble. now visitors can explore a former brewery sela and an escape tunnel arnold got inspired to explore the linz underground in paris. when i was studying urban regional planning in 1988 i got to know some parisian urban planners that's how i met a bunch of people who explore parisian catacombs there were 3 rival groups. i helped one carry out measurements and accompany them for 2 days that got me hooked when i returned to berlin i told myself i had to find out what lies below what was