Multiple Yorkshire stone paving slabs have been stolen from a Grade 1 listed bridge in Ferrybridge.
Police are appealing for witnesses to the thefts, and will be increasing patrols in the area.
The bridge, which crosses the River Aire, has stood for more than 200 years, and is one of the town's best known landmarks.
Photos provided by West Yorkshire Police show the extent of damage to the site, close to Ferrybridge Power Station and the A612.
Councillor Tom Gordon said he had been aware of the thefts for several weeks, and believed the thieves were using a car or forklift to access the bridge.
He said: "It's been going on for a couple of weeks now. The police were made aware and as a result of that the council have got a bridge engineer involved.
"At the end of teh day the responsibility is 100 per cent with the people who are vandalising and criminally stealing the stone.
"One of the things that's really surprised me is that growing up I didn't really appreciate the history and culture that Ferrybridge and Knottingley have. We've got such a thriving community of people who are involved.
"I must have had at least half a dozen residents get in touch over the weekend. It's an ice little walking route and people walk their dogs and with their children.
"When we have limited leisure facilities in the area we need to Sevres our nice green spaces."
Coun Gordon said he was concerned that the theft might lead to increased anti-social behaviour in the area.
A statement from West Yorkshire Police said: "We are appealing for any witnesses or any information that will assist in our investigation.
"The photographs below show just how may slabs have been removed for this historic bridge.
"Police will be patrolling the area in response to these thefts and conducting enquiries with local business, but would ask the public to be vigilant and report any suspicious activities immediately via 101 or 999.
"Local NPT officers have also been in contact the local councillors and are now actively assessing what best can be done to prevent any further incidents occurring.
"It is without question that these acts of targeted theft on a local historic landmark are beyond reproach and an insult to local residents."