Bornholm is one of the Danes' most popular vacation spots. This easternmost island (just off the southern tip of Sweden) has great beaches, small fishing villages, hiking trails and bicycle routes. The marked trails in the Almindingen Forest take you past ponds and, in the spring, lilies of the valley. The trail to the remains of Hammerhus, Scandinavia's largest castle, is gorgeous. Of special architectural note are the round churches built in the 12th century. These whitewashed stone buildings, with their 6-ft-/2-m-thick walls, doubled as fortresses during enemy attacks. (The best church is at Oesterlars, outside of Gudhjem.) Bornholm is famous for its glass and ceramics, as well as its herring—herring fans will no doubt enjoy the herring museum in Hasle. There is also a museum of art and archaeology at Ronne. We suggest at least one night on Bornholm. The island is a one-hour ferry ride from Ystad, Sweden, which is a three-hour drive from Copenhagen. 100 mi/160 km southeast of Copenhagen.