The Old Town Hall on Kauppatori, the central market square of Old Rauma, dates from 1776 and is one of the few stone buildings in the wooden quarter. It served as the town hall until 1965 and now houses the Rauma Museum's local history collection — silverware, ship models, period furniture, and ethnographic material relating to the town's lace-making and shipping traditions.
The building itself is the main interest: the council chamber upstairs is preserved with its original panelling and the merchant-class portraits of long-dead local burghers staring down from the walls. The basement holds a vaulted cellar with rotating exhibitions. The square outside hosts a daily produce market in summer and is a good vantage point for watching Old Rauma's everyday rhythm.