Allouis longwave transmitter

The Allouis longwave transmitter is a radio facility featuring two metal towers reaching 350 meters in height, among France's tallest structures. The installation uses these towers to broadcast signals across the entire country.

The original facility was established in 1939 and destroyed during World War II, then rebuilt in 1952 with enhanced transmission technology. This reconstruction made it capable of stronger coverage across France.

The station once connected people across France by transmitting radio news and programs into millions of homes daily. When broadcasting ended in 2016, the facility shifted its purpose to serving technology infrastructure instead of listeners.

The site is not open to visitors as it operates as a secure facility with sensitive electronic equipment in operation. It can be best viewed from a distance, such as from nearby roads or viewpoints in the surrounding area.

Since 2017, the facility broadcasts the ALS162 time signal that synchronizes millions of public clocks and railway systems across France. This ultra-precise signal also controls medical devices and air traffic control systems.

Location: Allouis

Inception: 1939

Official opening: 1939

GPS coordinates: 47.16958,2.20458

Latest update: December 7, 2025 10:08