Astronomical Observatory of Lisbon

The Astronomical Observatory of Lisbon is an observatory and museum in Alcântara featuring a distinctive central circular room with a decorated vault supported by eight sturdy columns. Located about 140 meters above sea level, it houses a collection of historical instruments used for observing the sky.

Construction started in 1861 under King Luís I, and regular observations began in 1867. The facility later attracted prominent scientists who conducted important measurements that advanced astronomical knowledge.

The building preserves instruments from the 1800s that show how astronomers once studied the sky. The rooms tell the story of how this science evolved through their original furnishings and layout.

Visitors can take guided tours and explore various sections with historical instruments to understand how astronomy worked from the 1800s to today. The site opens during daytime hours and is easy to reach, perfect for visiting between other city activities.

The building contains multiple pendulum clocks positioned between the columns that have measured time across many decades. These clocks reveal how astronomers once needed exact timekeeping for their observations.

Location: Alcântara

Official opening: May 6, 1878

Elevation above the sea: 140 m

Website: http://oal.ul.pt

GPS coordinates: 38.71054,-9.18751

Latest update: December 12, 2025 12:04