Sitting at an Outdoor Cafe -- Because of Copenhagen's long gray winters, sitting at an outdoor cafe in the summer and drinking beer or eating is always a favorite pastime. The best spot is at Nyhavn (New Harbor), beginning at Kongens Nytorv, where you can enjoy ice cream while admiring the tall rigged ships with bowsprits moored in the canal.
Going to Tivoli -- This is the quintessential summer adventure in Copenhagen, a tradition since 1843. It's an amusement park with a difference -- even the merry-go-rounds are special, using a fleet of Viking ships instead of the usual horses.
Strolling Strøget -- In Danish, the word strøget means "to stroll" -- and that's exactly what all born-to-shop addicts do along this nearly 1.2km (3/4-mile) stretch, from Rådhuspladsen to Kongens Nytorv. For a change of pace, midway along the Strøget's length, consider a detour onto the Vestergade, which runs parallel to the Strøget. It's lined with historic buildings and a roster of cozy bars.
Exploring Alternative Lifestyles -- Not for everybody, but worth a look, is a trip to the Free City of Christiania, on the island of Christianshavn (bus: 8 from Rådhuspladsen). Since 1971, some 1,000 squatters have illegally taken over 130 former army barracks (spread across 8 hectares/20 acres) and declared the area a free city. You can shop, dine, and talk to the natives about this community with its own doctors, clubs, stores, and even its own flag. Exercise caution here, however; there are pickpockets about.
Charting the Development of Modern Danish Design -- Two museums offer an overview of furniture designs that changed the look of the post-World War II universe. They include the Danish Design Centre (www.ddc.dk), opened in 2001, and the older, more extensive, and more eclectic exhibits within the always-fascinating Copenhagen Museum of Decorative and Applied Art. Hungry for more? The comprehensive collections at Louisiana, in Humlebæk, almost always focus on some aspect of the "structural vigor" of top-notch Danish design, in permutations that are wide and broad enough to keep you absorbed and fascinated for at least a day.