Bridgend County Borough Council is working with South Wales Police after the historic Cefn Cribwr Ironworks site was targeted by vandals twice in one month.
Last month, the lock on the front gate of the scheduled ancient monument, which is also known as Bedford Ironworks, was found to have been cut off and a wall inside the charging house was damaged.
It was discovered last week that the same wall had been damaged for the second time in a month, after repairs costing more than £600 were carried out on the wall last autumn.
The damage has been reported to South Wales Police as a heritage crime and officers will patrol the area.
Heritage crime is any unlawful activity which harms assets including listed buildings, scheduled monuments, historic parks, gardens and landscapes.
The Leader, Cllr Huw David, who is also the councillor for Cefn Cribwr, said: “I’m sad to hear that this nationally important site has been damaged by vandals. The Bedford Ironworks is very significant in the history of the development of industry in South Wales.
“The area is popular with dog walkers, joggers and cyclists and I would urge anyone who witnesses any suspicious activity to report it to police by calling 101.”
A new lock has now been fitted at the site, which is currently closed for repair work to be carried out to the blast furnace. The works, which are one of the most complete examples of their kind in Britain, were built by John Bedford, who moved into the area in 1770.
Bedford built a blast furnace in the 1780s and sank pits to mine ironstone and coal, as well as founding a forge and brickworks. The ironworks began to decline after his death in 1791 but coal mining and brick making continued throughout the 19th century. Industrial activity at Bedford Park ceased after World War I.
The ironworks is a scheduled monument and the individual structures are also listed buildings. Most other early ironworks were modernised as technology moved on and the original features were lost but at Cefn Cribwr the blast furnace is well preserved and the end wall of the casting house survives almost intact.
The monument is classed as of national importance for its potential to enhance and illustrate our knowledge and understanding of the development of the iron industry in Wales.
Image copyright: Bedford Ironworks by Lisa Baker, 2020,