The X Files filmed at Queen Alexandra's House, London. The entrance used in the elders' gathering is this Kensington Gore building, next to the Albert Hall.
Probable Named in published production coverage; the coordinate is the place itself, checked against a gazetteer. This is a street or a long feature — the coordinate is a representative point on it, not a single spot.
Planning the trip? The United Kingdom travel atlas covers money, language and getting aroundand everything filmed in London is on one page
Venture keeps every scene location on one map, sorted by how far you'd have to walk. Open it in London and it tells you what was shot around you, how to get there, and whether you can actually go in.
Download Venture for iOS Android