The Somerset Brick and Tile Museum, in East Quay, Bridgwater, has suffered successive attacks over the last few years, the Bridgwater Mercury reports.
Last September, a gang of youths pulled down shuttering and smashed tiles against the walls of the Grade I listed building.
Lead has been stolen from the roof, there have been several attempted break-ins and when it is closed the site is a meeting place for skateboarders who have damaged the walls.
But now museum bosses have clamped down once and for all by erecting vertical metal railings
to prevent people climbing over.
They also intend to install metal gates
to keep the skateboarders away.
David Walker, keeper of social history for the Somerset Heritage Centre and Library, which owns the brick and tile museum, told the newspaper: "I appreciate people enjoy skateboarding [but] they are damaging the structure of the site and it costs money to repair it.
"The lead was stolen a couple of years ago but we haven't been confident enough to put it back until the perimeter security has been improved as we run the risk of it being stolen again."
The Brick and Tile Museum shows visitors how the bricks, tiles and terracotta that were used to create the look of towns like Bridgwater were developed.