Mocha, also known as al-Mukha, is a port city on the Red Sea coast in Yemen.

In London Labour and the London Poor edition: 

Phase 1

Tom-tom Players. (Volume 3): "I come from Mocha, and so does Peter, my companion; only his father belongs to what we call the Abshee tribe, and that’s what makes him so much darker than what I am. The Abshee tribe are now outside of Arabia, up by the Gulf of Persia. They are much the same as the Mucdad people,—it’s all the same tribe like."