Swiss Tectonic Arena Sardona

Centred on the peak of Piz Sardona, this nature reserve has held Unesco World Natural Heritage status since 2008. A geologist's dream come true, it's one of the best places in the world to observe mountain creation and plate tectonics, thanks to the Glarus Overthrust. This razor-sharp "magic line" that slices across the rock faces of Switzerland's eastern Alps denotes where 250- to 300-million-year-old rocks were pushed some 40km on top of younger, 30- to 35-million-year-old rocks.