There are three great church ruins from the 12th century: St Peter´s, St Lawrence´s, and St Olof´s. The brick church of St Mary was built in the early 13th century by Dominican monks. It is the oldest building still in use in the town and is the home of the Sigtuna congregation of the Church of Sweden (Lutheran). Nearby is the Town Hall from 1744, considered the smallest in Scandinavia. Most of the wooden houses along The High Street (Stora gatan) date back to the 18th and 19th centuries and are surrounded by verdant gardens.
Sigtuna has the same street planning today as when founded in 970, making this town very unique. Stora Gatan is still the town’s main artery, with shops, cafés and restaurants decorating both sides of the pedestrian thoroughfare.
There are a lot of castles in the Sigtuna area. Make sure to visit Skokloster Castle; one of the great baroque castles in Europe. It was built between 1654 and 1676 – a period when period when Sweden became one of the major powers in Europe.