A Horncastle man fears someone could be seriously injured - by falling masonry from the town’s 2,000-year-old Roman wall.
One of the best preserved sections of the wall is on a private footpath off St Mary’s Square.
However, two sizeable sections of the historic structure have recently collapsed and fallen onto the footpath.
Pensioner Ronald Marney - who lives in a neighbouring property - believes it’s lucky someone was not injured.
Now, he’s calling for action to be taken to make the wall safe.
Mr Marney told the News: “It is very dangerous. One of the pieces that fell off is the size of your head - the other is two or three times bigger.
“It’s lucky that no-one was walking by at the time. They could have been seriously injured.”
The wall - believed to have been built to protect the town from raiders who travelled across the North Sea - stands above the level of the footpath.
Mr Marney said he thinks the whole structure could be in danger of collapsing.
He added: “A lot of it is down to age and, sad to say, neglect, but there is a serious problem with tree roots which have loosened a lot of the masonry.
“I don’t feel safe next to it. The whole lot could come tumbling down which, apart from the safety aspect, would be a great shame.
“I can’t believe that someone isn’t doing something to protect a very important piece of history.
Mr Marney admitted identifying who owns the section of wall was a problem.
“He added: “I’m pretty sure it is not the responsibility of any of the property owners.
“I don’t know if it’s the church or some other organisation. Surely, it can’t be that no-one cares.”
Mr Marney confirmed he contacted the town’s Historic and Heritage Society.
Mary Silverton, from the Society, said they were pressing English Heritage to take responsibility for preserving the wall.
She added; “We share Mr Marney’s concerns.
“Other sections of the wall are also in a poor state.
“We have been asking for something to be done for months but it seems to be taking for ever to get someone to take responsibility.”