Guastavino tile ceiling

At least, I think it is — I’ve only ever seen two Guastavino ceilings before, one in midtown Manhattan (under the Queensboro Bridge) and one in Berkeley (in the Hearst Mining Building), so I can’t be positive, but I think this is another one, down by New York’s City Hall. 

Guastavino was a 19th-century Spanish architect who brought his tiling method to America and patented it here. Beautiful, eh? And I thought these arches were pretty nifty, too.