It looks like any ordinary hotel.
But take the lift to the top of Hotel Viru in the Estonian capital, and then walk up a flight stairs, and its secret past is revealed.
The hidden 23rd floor was in fact used by the KGB for many years.
The old communications hub for spying operations in the region, with radio links to Moscow, is now being turned into a museum.
Hotel spokesman Peep Ehasalu said: “All the dangerous Western people stayed here and it was also the meeting place between Western and Soviet people, so it had to be watched.”
Foreigners who stayed in the hotel were often spied on during the 1970s and 80s.