The Prancing Pony is a sedate drinking establishment on Horspath*(A4), close to the Deosil Gate, where one's thirst may be quenched in genteel, sedate, surroundings.
The Prancing Pony Tea Rooms, to be precise. The distinct impression is gained that any Dark Riders smashing down the city gate and hunting for Hobbits would be glared at and firmly told to leave. And they'd go. Probably has a sign on the door saying "No Travellers".
To another drinking establishment nearby to a city gate locked at nightfall, in a different dimension, where travellers are welcomed (except Black Riders) and drinks dispensed.