Sekinoo Falls, Waterfall in Miyakonojō, Japan.

Sekinoo Falls is a waterfall in Miyakonojo, Miyazaki Prefecture, formed where a river drops over a wide ledge of volcanic rock and fans out into a broad sheet of water roughly 130 feet (40 meters) wide and about 60 feet (18 meters) tall. Below the drop, the water collects in a natural pool enclosed by steep rocky walls.

The falls cut through welded tuff from the Kakuto caldera eruption about 330,000 to 340,000 years ago, flowing along the rock's columnar joints. In the Meiji era, the Otoko and Onna falls were carved into the rock as a spillway and intake for the Hokumae irrigation channel. The upstream pothole field was designated a national natural monument on 18 February 1928.

The falls are linked to a legend of Oshizu, an 18-year-old woman said to be the most beautiful in the domain, who poured sake for the lord Kitagō Suketada at a moon-viewing banquet and, ashamed, threw herself into the pool with the cup. Her lover Tsuneyuki carved a poem on the rock with a spear; on moonlit nights a vermilion cup is said to rise from the pool.

The falls sit in the Michi-no-eki Sekinoo area of the Mochio-Sekinoo Prefectural Natural Park, with parking and a campsite and cafe nearby, so a day trip works. The Oh-taki, the 18-metre main fall, is reached by paths; the two side falls, Otaki and Metaki, are Meiji-era channels cut into the rock. The potholes lie 600 metres upstream along an 80-metre-wide riverbed.

The suspension bridge over the pool below the falls sways gently as you cross it, placing you at almost the same height as the falling water rather than looking up at it. Unlike many waterfalls, the width here is much greater than the height, which gives the water a wall-like appearance rather than a narrow plunge.