My local city, Canterbury, has an underwater sculpture in the River Stour created by Jason DeCaires Taylor.

 

 

It really is a beautiful piece, particularly at night when it is illuminated. 

The work draws reference to Sir John Everett Millais’s celebrated painting Ophelia (1851-1852). The pose of the figures and the materials used respond to the flow of water along the river and to the refracted colours of its fauna and substrate. As the surface tension and volume of water changes through the seasons, and the effects of light alter through the day, so what is seen of the sculptures changes. I've walked past it many times and thought I'd try and find out a bit more about the artist. 

Jason's underwater sculptures can be found in various locations around the world, the largest installation being in Cancun, Mexico.  Consisting of 500 life size sculptures, made from materials to encourage coral growth to redress the destruction caused by 750,000 visitors a year who visit Cancun.