Towering 52m above the waves 25km offshore from Hanko, the Nordic countries' tallest lighthouse was built in 1906 to protect ships from the perilous archipelago waters. It was damaged extensively during the Continuation War by the departing Red Army but has been refurbished. There are historical exhibits downstairs and fabulous views from the top.
In the summer months, you can reach Bengtskär with Marine Lines from Hanko and with the Rosala & Bengtskär Booking Office from Kasnäs or Rosala. If you wish to spend the night, the lighthouse also contains simple but panoramic accommodation (single/double/family rooms €120/188/280).