Anonymous, vaguely public sex between men has probably been part and parcel of the city's fabric since it was called Londinium. Historian Rictor Norton traces it back to at least the 1600s in his book Mother Clap’s Molly House.
We use numerous terms to refer to it— it can be cottaging, cruising, or dogging. The first two differ mainly in locale—be it a public lavatory or public lands. Cottaging and cruising refer to actively seeking sexual encounters, whereas dogging is the voyeuristic seeking out of public sex as a spectator.
While, strictly speaking, this activity is not illegal, “it is often considered taboo, and there are few dedicated spaces for cruising", Anup Kayastha, owner of 5LetterWords.org, told The Roost. "Instead, practitioners often rely on ambiguous locations that can be difficult to identify”. Indeed, the Human Rights Act’s article 8 has been interpreted to enshrine the right to engage in sex outdoors. In the UK, the potential illegality comes into play when others witness the goings on and there is sufficient evidence to prove in court that a third party saw—or that there was a high likelihood of them seeing—the public sex.