"I guess we're friends now!"

Because humans have almost never gone there for 60 years, the Korean DMZ has become a refuge for several endangered species such as Siberian tigers and red crowned cranes.

Written by Icelandic composer Jón Leifs in 1964, the piece called Hekla, Op 52, requires four sets of rocks hit with hammers, steel plates, anvils, sirens, cannons and metal chains to play.