Kalmar is one of the oldest cities in Sweden and home to Sweden's best-preserved Renaissance castle. Although it is a thriving commercial center today, Kalmar still retains many 17th-century buildings and sea captains' houses. The 13th-century Kalmar Castle has served as fortress, distillery, granary, and prison and now houses the county museum. Kalmar Castle, the Old Town and Kvarnholmen are the main attractions with traces of the past found in architecture and cultural artifacts. The town has a vibrant nightlife with musical events, theatre, pubs, dancing, and in the summer, outdoor venues and sidewalk cafés where you can relax after the day's activities.