The Fort de Seclin is trapezoidal in shape, with a central artillery position on top of barracks and support facilities, surrounded by a defended ditch and counterscarp.

[1] The fort did not see significant action during World War I, as it was to the rear of Lille and was among the last positions to be overrun.

The Germans took over the fort and used it as a supply depot until 1918, when it was occupied by British forces from the 68th Battalion, King's Liverpool Regiment, as they advanced into Lille.

[2] In the most notable event, seven employees of the French national railways were arrested and accused of sabotage, spying and armed resistance.

The six male prisoners were executed by firing squad at the Fort de Seclin on 7 June 1944.