A 19th-century octagonal wooden daymark tower — a pooki in Finnish — on the small island of Tasku in the Raahe archipelago. Daymarks were unlit navigational aids that helped sailing ships find safe channels through the shallow, island-littered waters of the Bothnian Bay.
The tower is about 20 metres high, painted in red and white horizontal bands. It is no longer in active use as a navigational aid but has been preserved as a heritage building. Reaching it requires a boat — local operators run summer cruises out of Raahe harbour. The view back across the archipelago and over to the open sea is reward enough on a clear day.