Perret tower (Grenoble)

Perret tower
La Tour Perret
The Perret tower as seen from the Paul Mistral Park
General information
Status	closed from 1960 and waiting for works
Location	Grenoble, Paul Mistral park, France
Coordinates	45°11′05″N 5°44′07″E / 45.18472°N 5.735280°E / 45.18472; 5.735280
Opening	6 September 1925, by the council president Paul Painlevé, Edouard Herriot and
Cost	385,000 FRF (in 1924)
Owner	Grenoble city
Height
Antenna spire	108 metres (354 ft)
Roof	95 metres (312 ft)
Technical details
Floor count	Ground floor and 3 patios
Lifts/elevators	2
Design and construction
Architect	Auguste and Gustave Perret
Engineer	Auguste Perret

The Perret tower, also named the "Tower to look at the mountains", is an observation tower located in Grenoble, in the Paul Mistral public park. It is the first tower built in reinforced concrete in Europe. In 1998, it was officially declared to be a national heritage site. It was built in the field of the International Exhibition of Hydropower and Tourism where it was the orientation tower and the symbol of the exhibition. Nowadays, it is the last vestige of this exhibition.

Perret tower stands 95 metres (312 ft) tall. Its section is octagonal. Its foundations are 15 metres (49 ft) long, made of 72 vertical stakes in reinforced concrete gathered at the top by a slab and placed on a hard gravel layer. The framework is compound of eight vertical poles. The tower diameter is 8 metres (26 ft) at the base. The last floor is reachable by helical stairs (visible in the top openwork part) or by lift.

Auguste Perret, with the assistance of Marie Dormoy, art critic, came to Grenoble for two years, to do conferences and meet political and artistic circles in order to show its "reinforced concrete order"; a reference to the antique orders. Made of the first reinforced concrete, it is also the first free project made by Auguste Perret, its architect.

The tower is the sum of an architectural and structural thought particularly modern and exact. It is a reinforced concrete structure whose formworks are modular and repetitive, and the prefabricated fillings are re-used from the "Notre-Dame du Raincy" church. It provoked all criticisms during its construction but it is a success which cost half as much as the other edifices of the exhibition.

Also named orientation tower, not because the four cardinal directions are molded at its top but because an orientation table asked by the , encircles it at the 60 metres (200 ft) level. This orientation table allowed tourists to locate the surrounding mountains with the pleasure to show a unique panorama on the Alps and Grenoble because its height is about the same as the three towers of the Île Verte in Grenoble. So, it is one of the highest buildings in Grenoble.