Usui Pass Railway Heritage Park

Usui Pass straddles the mountainous border between Gunma and Nagano prefectures along what was once one of the most challenging stretches of Japan's old Nakasendo highway. Today it is best known for the Usui Pass Railway Heritage Park, where you can walk through abandoned brick-lined tunnels and along the old Abt rack railway route that once hauled trains up the steep gradient. The 6km hiking trail between Yokokawa and the pass takes you across striking brick viaducts, including the iconic Megane-bashi (Spectacles Bridge). Rail enthusiasts and hikers alike will find the blend of industrial archaeology and mountain scenery hard to resist.