Festivals and events: Look out for free concerts and open-air performances during the summer months. The Bergen International Festival is the big one and has a large free outdoor programme.
Markets: Whether you buy or not, a wander around Torget's open-air fish market is quite an experience (though smelly)! The displays of prawns and crab-claws, dried cod, herring and other varieties of marine life on slabs, in tanks, under the knife and in packets is quite something.
Free museums: Bergen has a terrific stock of museums, many free, such as the Bergenhus Fortress Museum (one of the city's better museums) and the Buekorps Museum, which explores the rich history of Bergen's Boys Brigade.