The Ruhnu Lighthouse is a cast-iron tower built in 1877, standing at the southeastern end of the island. It is about 34 metres tall and still serves as a working lighthouse, its light visible for up to 20km on a clear night. The tower has the elegant, tapered proportions typical of 19th-century lighthouse design.
The lighthouse can be reached on foot or by bicycle from the village in about 30 minutes. The path runs through mixed forest and emerges onto the coastal meadow where the tower stands. From the base there are good views over the Gulf of Riga. The lighthouse is not open for climbing, but the exterior and the surrounding landscape justify the walk.
Local tradition attributes the design to Gustave Eiffel — a claim that cannot be fully verified but has become part of the island's folklore. Whether or not Eiffel's drawing board produced this particular tower, it is a handsome piece of Victorian industrial design in an unexpectedly remote location.