Police are investigating a fire that damaged two medieval doors at Lincoln Castle in the early hours of Tuesday, June 11.
The fire was reported to Lincolnshire Fire and Rescue at around 3.45am and was put out quickly using two water backpacks.
Two wooden medieval doors leading to Lucy Tower have been damaged in the fire.
Lincolnshire Police also attended the incident and searched the grounds using police dogs. No intruders or trespassers were found.
Police suspect the cause of the fire was arson and are investigating. They are calling for any witnesses to get in touch via 101 number quoting incident 29 of June 11.
Rachael Thomas, Castle development manager, said: “It’s disappointing that somebody would want to do this to the castle.
“Thankfully, the fire was quickly extinguished, but there was damage to two doors leading up to Lucy Tower.
“We’re now assessing the damage to see whether they can be repaired or need to be replaced. In the meantime, we’ll be helping the police with their investigations.”