Stockholm's approach through the archipelago is breathtaking. Spread over 14 islands and crossed by 57 bridges, it's called "the city that floats on water." Visit Djurgården for the Vasa Museum and the Skansen open-air museum, wander Gamla Stan's medieval streets, and see nearby UNESCO sites: Birka, Skogskyrkogården, and Drottningholm Palace, home to the royal family since 1662.

Turku, Finland's oldest city, blends medieval history with modern life. Start at Turku Castle on the Aura River, a 13th-century fortress, then visit Turku Cathedral, one of Finland's most important Gothic landmarks. Art highlights include Wäinö Aaltonen Museum, Turku Art Museum, and Aboa Vetus Ars Nova, built over medieval ruins. Enjoy riverbanks, bike paths, or boat cruises, and try local foods at Market Square: salmon soup, berries, and rye bread with butter.

Helsinki, Finland's capital and largest city, is a cultural hub with museums, galleries and theaters, including the Ateneum's nearly 30,000 works of art. Rebuilt under Russian rule in the 19th century, its neoclassical center features Senate Square, boulevards, parks and grand architecture. Market Square offers local crafts and salmon soup. Nearby Suomenlinna, a UNESCO fortress island reached by ferry, has museums and parkland.

Tallinn's UNESCO-listed Old Town is one of Europe's best-preserved medieval cities, with 13th-16th century churches, homes, and public buildings from Hanseatic merchants. Highlights include St. Olaf's Church, Alexander Nevsky Cathedral, Toompea Castle, and the Gothic town hall. Finish with a stroll in Kadriorg Park and its art museum in an 18th-century Russian palace.

Warnemünde is a charming resort town with a popular beach, promenade, and gabled fishermen's houses. Nearby Rostock features a university founded in 1419, St. Mary's Church with its astronomical clock, the 13th-century Town Hall, and an old town. Inland, visit fairytale-like Schwerin Palace or Berlin, with Brandenburg Gate, the Reichstag dome, the East Side Gallery, Museum Island, Topography of Terror, the Jewish Museum, the Allied Museum, and Charlottenburg Palace.

Karlskrona blends naval heritage, a friendly feel, and easy access to outdoor adventures. In 1680, Karl XI chose the southern archipelago as Sweden's naval base. Trossö's 17th-century grid is still the Baroque heart of the city, now spread over 33 islands. From the town square and its landmarks to the Naval Port, Naval Museum, and Björkholmen, many sights are walkable. The old fish market is now the gateway to the archipelago.

Perched on a harbor rock, the Little Mermaid welcomes visitors to Copenhagen, a lively Danish capital famed for happiness, good food, free education and healthcare, and a 37-hour work week. The city blends modern architecture, world-class museums, charming canals, and Old Town streets in the world's oldest kingdom, plus 15 Michelin-starred restaurants and Strøget, the world's longest pedestrian shopping street.