Cal follows Sam outside, scarcely glancing back as the door falls shut behind him. His last visit to another world was, quite literally, a visit to America's house.

This is slightly different. (Even though, somewhere in the back of his head, Cal would not be surprised if Spain went walking past.

Visiting the Hetaliaverse has an interesting effect on a person.)

He pauses to get his bearings, looking around. Being a city is about where Madrid's resemblance to New York ends, and he's trying to take it in.