A 400-year-old door at Exeter Cathedral is thought to have the oldest cat flap in the world.
The hole, leading to a cavity behind a large clock, was made in the 16th century so the priest's cat could "catch rats and mice".
Cathedral historian and author Diane Walker, told the BBC: "This door has lots of legends associated with it, but there are facts that we also know, and there is a hole at the bottom of this door.
"We have a record that says there was a payment of eight pence for the carpenters to cut a hole in this door for Bishop Cotton, and Bishop Cotton came here in 1598."
It is understood rodents have been attracted to that specific cavity for centuries as the clock, which was installed in 1376, used to be lubricated with animal fat.
She continued: "There are likely to be holes cut in other doors which haven't got a record of when they were cut, so who knows, but it is nice to think ours is one of the earliest.
"We haven't checked all the details and it may be there are holes in other places that don't actually have a date. We are fortunate that we know it was from Bishop Cotton's time here because we have got the record of payment to the carpenters."