Museum Observatório Astronómico de Lisboa in Lisbon

You're standing in the Tapada da Ajuda, a large green park on the hills of Lisbon, right by the Astronomical Observatory. Start with the central building and the dome on top. That's where the big telescope lives. Now look south. There you'll spot two smaller domes, also full of instruments. And turn around for a second: from up here you look out over the Tagus river.