Green’s Dictionary of Slang

Pool, the n.

Liverpool.

1882		Manchester Courier 28 Jan. 10/5: I had to leave ‘the Pool’ to-day.
1935		Thieves Slang ms list from District Police Training Centre, Ryton-on-Dunsmore, Warwicks 11: The Pool: Liverpool.
1963		Mersey Beat 26 Sept.–10 Oct. n.p.: If they could sing, they too would leave the ‘pool for the money. The Beatles are only earning a living.
2000		N. Griffiths Grits 312: Obviously a couldn’t go back ter the ’Pool after tha.