Market Square is the old civic centre of Lutsk, a modest but atmospheric space near the castle and cathedral quarter. It dates back to the medieval town, when the market was framed by churches, town buildings, and deep brick cellars used by merchants.
The square is best treated as part of an old-town walk rather than as a single monument. From here you can link the castle, the Jesuit cathedral, former monasteries, and the small side streets that show Lutsk's layered Polish, Lithuanian, Jewish, and Ukrainian past.