Osawa Pond is Japan's oldest surviving artificial pond, created 1,200 years ago to mirror the shape of China's Dongting Lake. It was designed to be enjoyed from a boat, not from the shore.

The covered corridors feature 'nightingale floors' that chirp when walked on, the same anti-intruder system used at Nijo Castle. A hidden device creates the sound to alert of footsteps.

Emperor Saga's handwritten Heart Sutra, which supposedly ended a plague during the Heian period, is displayed to the public only once every 60 years. The next viewing won't be until 2078.

Ōsawa Pond is one of Daikaku-ji's signature sights; the Japanese text describes it as a large pond preserving the feel of a Heian-period garden.