Statue of Marie Curie

Sanbutsu-ji is a mountain temple complex that's famous building, Nageiredo (投入堂, literally "thown-in chapel"), is built into the side of a cliff. The building is a National Treasure and a unique site in Japan. Visitors wishing to make the trek to the Nageiredo (or to visit any part of the complex) should be aware that you must travel in a group of 3. Single visitors are not permitted to ascend. If you arrive as a single traveler, you will be denied entry and forced to wait for another single traveler (or group willing to take you in) to be paired with - it is often described as "the most dangerous National Treasure in Japan".