DOCTOR: So a hotel, but instead of rooms, time portals, yeah?

TREV: Yeah.

DOCTOR: Oh! Oh! That stone door up there, that is actual stone, live from the Stone Age. God... Live from a submarine. Mesopotamia. (a leaning door) Oh, come on, got to be Pisa.

TREV: Yeah, Pisa.

DOCTOR: Ha! (looking at leaflet) Ancient Rome, the fall of Troy, your favourite assassination. Package deals for all of history's biggest hits. No wonder there was no room at the inn.