"The Gardener's Arms and the Nag's Head, the Druid's Head near the theatre, and the Turf in Hell Passage"
These are (or have been) actual pubs in Oxford.
The Gardener's Arms, The Nag's Head and The Turf are still in existence today, although Hell's Passage (the location of The Turf) has been renamed St. Helen's Passage.
Legend has it that it was at The Turf that the former U.S. president Bill Clinton famously did not inhale!
The Druid's Head closed down in 1934.