Cell towers in Mery-sur-Oise (Val-d'Oise)

Masts stand at Bois du Défai, 2 Chemin des Boeufs, 11 Residence le Bel Air, Rue des Quatres Chemins, 88 Chemin de Pontoise and Route de Sognolles.

The tallest structure is a 46 m pylon at Bois du Défai. The median is 30 m, above the Val-d'Oise median of 25 m.

Systems from 1995 are still on the register. Local 5G started with Free Mobile in December 2020; SFR followed in December 2021, Orange followed in April 2022. 2019 was the busiest year, with 18 new systems, most of them 4G.

Approved additions not yet in service are pending on one existing mast, for example SFR (5G 2100 MHz) at Bois du Défai. 3 Bouygues Telecom 5G transmitters are listed as technically operational — installed, but not yet declared commercially in service.

On 3.5 GHz, the fastest 5G band: Orange on all 4 masts, Free Mobile on all 3 masts, SFR on all 2 masts and Bouygues Telecom on 1 of its 2 masts.

2.4 km to the north-east, neighbouring Meriel has 5 masts declared.

Only one mast carries all four networks.

Among the 43 Val-d'Oise towns with at least five masts, Mery-sur-Oise ranks 34th by mast count. With 7 masts for 9,983 residents, or 7 per 10,000, it has more masts per inhabitant than the median for those towns (6).

Supports split between 5 pylons and 2 buildings.

Figures above cover installations declared to ANFR as in service or technically operational, as of October 2026; approved projects are not counted.