About halfway up the western coast of New Zealand’s southern island, Franz Josef Glacier is one of the most accessible glaciers in the world.

Still more than 12 km long, it descends to less than 300 meters above sea level, in the middle of a tropical forest. Along with nearby Fox Glacier, they’re the only two glacial formations on Earth that coexist with tropical plantlife.

According to Maori legend, Franz Josef was formed when a local woman named Hineukatere brought her lover Wawe climbing up Mt. Cook; when he fell to his death in an avalanche, Hineukatere’s tears froze into the glacier, giving it the Maori name (Ka Roimata O Hinehukatere, the Tears of Hinehukatere). Westerners renamed it in honor of the Austrian Emperor Franz Josef in 1865.

Franz Josef is one of the most volatile glaciers, occasionally seeing flow rates up to 70 cm per day (that’s about ten times the average). It’s been in a very rapid retreat since 2008, and worsening conditions on the terminal face have forced the closure of the glacier walk entrance; currently the only way onto the glacier itself is via helicopter tour.