In 2000 this open-air gallery was conceived as a way to bring people back to this rapidly depopulating, though enchantingly beautiful rural area of green fields and historical wooden farmhouses. Spread out over 770 sq km are scores of installations by Japanese and international artists, set as naturally as possible in the surrounding landscape. Catch a train from Echigo-Yuzawa Onsen to Tōkamachi (¥610, 30 minutes) and download maps online. You'll need a car to make the most of it all.
The area really comes to life during the summer-long Echigo-Tsumari Triennial (next up in 2018).