Green’s Dictionary of Slang

mount-faulcon n.

[lit. ‘mount falcon’; coined by lexicographer John Florio (c.1553–c.1625)]

the vagina.

[UK]Florio Worlde of Wordes.
[UK]G. Torriano The second alphabet consisting of proverbial phrases 108: Passar sopra il Monteficale [...] to pass over Monteficale, viz. to use carnal copulation with any woman; the English would say over her Mount-faulcon, the allusion lies in fica, a womans commodity.
[UK]Halliwell Archaic and Provincial Words II.
[UK]Farmer & Henley Sl. and Its Analogues.