Nachi-no-Otaki (Nachi Waterfall), 133m high with its water source in the forests of the Nachi Mountains, is the longest waterfall in Japan. This waterfall is the religious focus of Kumano Nachi Taisha Grand Shrine and Nachisan Seiganto-ji Temple and is still the primary object of nature worship. It is home to the deity of Hiro-jinja shrine, the auxiliary shrine of Kumano Nachi Taisha Grand Shrine.

Registered as UNESCO World Heritage 'Sacred Sites and Pilgrimage Routes in the Kii Mountain Range'.