Ancien observatoire astronomique de la Marine de Nantes

The former naval astronomical observatory in Nantes is a neoclassical structure with a square base and terrace top that rises 27 meters high. A staircase of 127 steps winds upward inside to reach the observation platform at the top.

The tower was built in 1826 by architect Étienne Blon as a training facility for naval officers in celestial navigation. It operated actively until 1887, serving the needs of French maritime education during that period.

The place served as a training center where sailors learned to read the stars for navigation at sea. This connection between astronomy and seafaring remains central to how locals understand it as an example of science put to practical maritime use.

The building sits on Rue Voltaire in Nantes and remains private property, so visits need to be arranged beforehand. It is best to contact the owners in advance to schedule an appointment to enter.

It remains the only intact naval observatory in France built specifically for maritime observations. Its preserved state makes it a rare reminder of how French sailors relied on astronomy for navigation at sea during the 1800s.

Location: Nantes

Inception: 1828

Architects: Étienne Blon

Architectural style: Neoclassical architecture

Height: 27 m

GPS coordinates: 47.21157,-1.56600

Latest update: December 9, 2025 20:26