Ōda City: Nima Sand Museum (World's Largest Hourglass) and Nakisuna (Singing Sand of Kotogahama and Nima Beach)

Ōda (大田市 Ōda-shi^?) is a city located on the coast of the Sea of Japan in Shimane Prefecture, Japan.^[1]

On October 1, 2005 the towns of Nima and Yunotsu, both from Nima District, were merged into Ōda, and Nima District was dissolved as a result of this merger.

The Nima Sand Museum museum features a large hourglass mechanism that automatically rotates from December 31 to January 1. It is designated the largest hourglass in the world, but is not officially registered in Guinness World Records. This museum officially opened in March 1991.

Built in 1991^[5] and located in the Nima Sand Museum, this hourglass is 5.2 metres high and contains around 1 ton of sand.^[6]

Singing sand, whistling sand or barking sand is sand that produces sound. The sound emission may be caused by wind passing over dunes or by walking on the sand.
Certain conditions have to come together to create singing sand:

1. The sand grains have to be round and between 0.1 and 0.5 mm in diameter.
2. The sand has to contain silica.
3. The sand needs to be at a certain humidity.

On some beaches around the world, dry sand will make a singing, squeaking, whistling, or barking sound if a person scuffs or shuffles their feet with sufficient force.^[2][3]  The phenomenon is not completely understood scientifically, but it has been found that quartz sand will do this if the grains are very well-rounded and highly spherical.^[4]

Singing sand dunes, an example of the phenomenon of singing sand, produce a sound described as roaring, booming, squeaking, or the "Song of Dunes". This is a natural sound phenomenon of up to 105 decibels, lasting as long as several minutes, that occurs in about 35 desert locations around the world.