A Living Underwater Environment Shaped by the Tides
Because Toriike is connected to the sea, its water level rises and falls with the tides. Differences in depth also create variations in water temperature and salinity, producing a complex aquatic environment where a variety of marine organisms can live.
These unusual conditions have made Toriike a popular destination for diving. Beneath the surface, the connection between the ponds and the surrounding sea creates an underwater landscape very different from an ordinary inland pond.
How the Mysterious Ponds Were Formed
The formation of Toriike began with a limestone cave that existed along the coast. Over time, waves gradually eroded and enlarged the cave. Eventually, parts of the cave ceiling collapsed, creating large sinkholes known as collapse dolines.
Seawater then entered these depressions, forming the two deep blue ponds that can be seen today. The geological processes that created Toriike are closely related to the limestone landscape characteristic of the Miyako Islands.
A Rare Karst Landscape
The area surrounding Toriike features a distinctive karst landscape known as karrenfeld, formed through the weathering and erosion of limestone. The site is also home to plants of considerable scientific value.
Because of its exceptional geological and natural features, Toriike was designated in 2006 as both a National Place of Scenic Beauty and a Natural Monument of Japan.
Other Sinkholes Beyond Toriike
Several other collapse dolines can be found beyond Toriike. One of them is Nabekoko Pond, which is also believed to be connected to the sea through an underwater cave.
A walking trail once allowed visitors to explore the surrounding area, but sections of the trail were damaged by a typhoon in 2016 and are currently closed.
A Fascinating Geological Wonder of Miyakojima
Toriike is far more than a pair of beautiful blue ponds. Its unusual connection to the ocean, dramatic depth, underwater caves, tidal movements, and surrounding limestone landscape make it one of the most fascinating natural sites on Miyakojima.
For travelers interested in geology, marine environments, diving, or unusual natural landscapes, Toriike offers a rare opportunity to see how the forces of the sea have shaped the limestone islands of Okinawa.