There are 2 large fountains in Rossio Square (also known as Pedro IV Square) in Lisbon, each with 4 mermaid statues. map
The bronze sculptures were created by sculptors Mathurin Moreau and Michel Lienard, and were installed with the fountains in 1889. They were created in Val d'Osne, France and then imported to Portugal.
References:
● http://en.wikipedia.org/wiki/Rossio_Square
● The Mermaids of Earth coffee-table book: See page 92 in the book about this sculpture.
232 statues. The myths behind them, the artists who made them, and where to find them. Delivered every week — free.