A favorite summer getaway for Danes, the laid-back Baltic island of Bornholm has rolling countryside and ruined castles. The island is home to four of Denmark's seven "rundkirkes," round churches dating from the 12th century. These unique churches were places of worship and also protection in times of pirate attacks, to which the island was vulnerable. The coastline mixes pearl white sand in the south with sheer granite cliffs to the north. The picturesque seaport of Ronne lies at the southwest corner of the island.