“The fountains at Peterhof in St. Petersburg (Russia) are immensely impressive, built on a grand scale. The Samson Fountain, which is part of the “Great Cascade”, has a number of mermaid statues.
Both the child and grown mermaids are twin-tailed mermaids, which was quite common for mermaid sculptures at that time in history.
The statues and the fountain date back to about 1730, and were created on the orders of Peter the Great, and were inspired by the French Château de Marly. The fountains are powered by water pressure from natural springs at a higher elevation, with no need for pumps.
More information on the Peterhof Mermaids page.