As Falkirk Council area’s most high profile historic “film set” it is now firmly on the tourist map as a must-see attraction for fans of TV series Outlander and movies including Outlaw King and Mary Queen of Scots.
The high number of visits in peak season means the old toilet facilities now need to be modernised to meet tourists’ expectations.
The new toilets should be open in around eight weeks, well after the main tourism season, but temporary facilities will be available in the meantime.
Historic Environment Scotland said: “There are planned alteration and improvement works to our toilets at Blackness Castle.
“These works involve a refresh and upgrade of existing toilet facilities with a high finish to improve the visitor experience.”
The toilets are in the one-time barracks block of the iconic 15th century fortress.