A private security firm has been drafted in to patrol the steps of Lancaster City Museum during opening hours.
Two security guards from Lancaster based Castlegate Security will be present at the entrance of the museum in Market Square during the day following long running complaints about anti-social behaviour.
Police patrols have also been stepped up in Lancaster city centre over recent weeks.
Visitors to the museum had previously been asked to use the rear entrance to the building.
A spokesperson for Lancaster City Council said: “A security presence has been commissioned for the City Museum to provide reassurance to staff and public using the building.”