Most were brothels, but others simply places to fuck in relative peace. Molly houses were spaces for female mimicry mock marriages and births of singing, of community and of sex. Probably deriving their name from the slang for a homosexual male, these were havens for those looking for same-sex interactions in a society where sodomy was still punishable by death. It was only in 18th century London that the first well-documented queer spaces started appearing, with 'molly houses' the place to head if you were looking for a gay old time. The first gay cruising grounds and gay brothels are likely to have appeared towards the middle of the 17th century, but evidence is limited. There's not a huge amount known about queer spaces in London before the 1700s a combination of poor documentation and the need for the upmost levels of secrecy means historians know very little about where exactly those looking for same-sex contact would have flocked.
The best way of doing that? A history lesson.