Rather a nice one, this, set up in honour of the Tallinn Sailing Regatta in the 2002 Olympics.
It's called 'Merineid, by Edgar Viies, and is placed to the side of the huge Viru shopping centre. It's on the left as you look at the centre from the Vana-Viru gate.
Nothing spectacular really, but its complexity is intriguing.
The Tallinn Olympic Yachting Center was built for the 1980 Moscow Olympics (when Estonia was still part of the former Soviet Union). I saw it from the bus on the city bus tour.