The site, which is on a prominent hilltop location, is a large parcel of land that contains several buildings, a monumental gate, gardens, and a small forest.

[1] In 1899, the architect François Giamarchi was commissioned to transform the east façade of the building (garden side) by adding a decorative relief of ionic columns supporting a cornice.

[3] In March 2010, the French Ministry of Culture classified the building and the large gate as protected historical monuments.

Flammarion's choice of the telescope was inspired by a similar instrument in the west tower of the Paris Observatory.

In 1906, German astronomer Max Wolf discovered a minor planet orbiting the Sun and named it 605 Juvisia in honor of the location of Flammarion's observatory.