cinque ports, n. — Green’s Dictionary of Slang

cinque ports n.

[‘a group of sea-ports (originally five, whence the name) situated on the south-east coast of England’ [...] ‘the five “Ports” are Hastings, Sandwich, Dover, Romney, Hithe, to which were added in very early times the “Ancient Towns” of Rye and Winchelsea’ OED; the genitals are in the ‘south’ of the body, plus play on port, that which is entered]

the female genitals and anus.

1660

Wandring Whore I 7: Lighting a pipe of Tobacco [he] gave those many-footed vermin (arising from inbred Lechery) such a rout at her Cinque ports, by thrusting in the small end of his pipe into one hole, then into the other, blowing the smoke at the other end of his Pipe, that they never durst venture to inhabit those Continents since.