Sisä-Hattu, Helsinki.

A little detour off the southern-most tip of Lauttasaari island is totally worth it – and worth getting your feet wet. The small island of Sisä-Hattu (i.e. “Inner Hat”, big sister to nearby “Outer Hat”) is best accessible at low tide and a fun picnic / swimming spot. Take your flip-flops or swimming shoes, you’ll need wade through a rocky route. Look for some engraved rocks dating back to as early as the 1700’s.