Is a “hidden rooftop” really hidden?

United Kingdom: When I first heard the phrase, I pictured a speakeasy behind a bookcase. In London, it’s more often a glass door in a building that’s already famous for its office space.

United Kingdom: When I first heard the phrase, I pictured a speakeasy behind a bookcase. In London, it’s more often a glass door in a building that’s already famous for its office space.