Historic Sites

Royal Observatory of Belgium

Founded mid-revolution, this Uccle hilltop observatory once operated one of the largest telescopes on Earth.

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Mathematician Adolphe Quetelet convinced King William I of the Netherlands to build it in 1826; it survived fighting during the Belgian Revolution before relocating to Groeselenberg hill in 1890. Its early-20th-century 100 cm Zeiss reflector ranked among the world's largest at the time. The site still runs live research in Solar physics, astrometry, and seismology.

What to look for

Located in Uccle municipality, Brussels; operated by the Belgian Federal Science Policy Office (BELSPO).

Royal Observatory of Belgium is one of 33 sights worth the detour in Brussels, all bundled offline in Voyage GO — download the Brussels pack and it sits on your map with no signal, filling your travel passport the moment you walk past.

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