The city of Paralio Astros (Astros Beach) in Greece has a sculpture known as the Stheno Mermaid.
The statue looks out over the Argolic Gulf and the city of Paralio Astros and its harbor. It is debatable whether it represents a mermaid or a serpent goddess – or maybe a combination of both. Stheno in Greek mythology is the sister of Medusa, and is often represented as a serpent goddess.
More data and photos can be found on the Stheno Mermaid page.