Thousands of pounds worth of damage was caused by “a large group of pre-teen youths” who smashed a hole in an historic wall.

An appeal for information has now been made after the vandalism, which took place in the Waltham Abbey Gardens on April 2.

It is estimated the initial work to repair the 16th century wall will cost around £1,000, and repairing the whole section could cost between £5,000 and £10,000 depending on how much stone work can be salvaged.

The Lee Valley Regional Park Authority (LVRPA) said the gardens are of great historical significance, and the incident has been reported to the police.

It is believed that the gardens could be the last resting place of King Harold, and an application has been made to exhume an unmarked grave after wall markings were investigated by author Peter Burke.

The wall has been taped off from the public and assessed by an expert from Historic England, ahead of specialist repair work.

Alex Farris, green spaces manager for LVRPA, said: “It is such a shame that these areas have been damaged because of mindless vandalism.

“Because it is unstable, it is also a health and safety issue and the safety of our visitors is our priority.

“We hope to restore the wall quickly and securely, whilst retaining its historical integrity so that the area can be fully enjoyed by our visitors and conserved for future generations.”

Anyone with information about the identities of the vandals should contact Essex Police by phoning 101.