Boglösa is the most compelling reason to leave central Enköping. The exposed rocks here carry Bronze Age and Iron Age carvings of ships, people, animals, footprints, and cup marks, made when this part of Uppland was closer to the water and tied into the Baltic trading world.
The best-known image is the Brandskogen ship, a long carved vessel more than four metres across. The site is open-air and modestly presented, so bring curiosity rather than expectations of a polished museum. It is much more rewarding with good light and dry weather.