Green’s Dictionary of Slang

caravansera n.

also caravansery
[SE caravanserai, a form of Oriental coaching inn where the merchant caravans could find food and shelter; ult. Per. karwan, caravan + sara, palace]

a railway station.

[UK]Hotten Sl. Dict.
[UK]Sl. Dict.
[UK]Newcastle Courant 2 Sept. 6/5: As ill luck would have it the Raven happened to be in that particular caravansera at the moment and gave chase.
[Aus]Crowe Aus. Sl. Dict. 15: Caravansery, a railway station.