People have been having sex on tombstones outside a church, and using them to take alcohol and drugs, police said.
Suffolk Police slammed the behaviour as "disrespectful" and has requested railings to protect the tombstones outside the historic St Stephens Church in Ipswich.
In a letter responding to plans to develop the town's Arras Square, the force said: "In publicly accessible but secluded locations such as this, it is sadly common to find raised tombstones being used as ‘tables’ to consume alcohol and drugs.
"They are also sometimes the site of sexual activity.
"In a religious setting, this anti-social behaviour is particularly disrespectful."
It recommended measures to "deter activity on top of the tombstones".
The force said this could be an enclosure for the whole tombstone - as is the case in St Clements Church - or a small railing about 20cm high around the top of the tombstone, as has been used elsewhere in the town.
The former parish church of St Stephens is a Grade II listed building.
Arras Square has had high levels of crime and anti-social behaviour, the force said.
It also recommended removable seating, CCTV to cover the whole site, and measures to make the areas less secluded.
The redevelopment plans will be discussed by Ipswich Borough Council at a planning meeting on Wednesday.
Want a quick and expert briefing on the biggest news stories? Listen to our latest podcasts to find out What You Need To Know