The House of the Four Winds is a small seaside landmark on a rocky point outside Hanko, remembered for its villa setting and long views over the water. It fits Hanko's character well: Baltic light, old resort-town atmosphere, and a landscape of rocks, pines, and villas.
It is best treated as a scenic stop rather than a major sight. Combine it with a coastal walk or cycle ride, and use it as one more piece of Hanko's summer-resort story.