The Czechoslovak Army Mine (Czech: Lom Československé armády, shortened to Lom ČSA) is an opencast lignite mine located in the Most Basin of the Czech Republic, located between the city of Most and the town of Litvínov.

[1] Originally occupying an area of nearly 5,600 ha at the foot of the Ore Mountains and under the gaze of Jezeří Castle, it was the biggest lake in the Kingdom of Bohemia.

Due to the requirements of the mining industry, and partially for health reasons, Lake Komořany was artificially drained at the behest of Prince Ferdinand Lobkowitz from 1831.

It was transformed from a small-scale mine to a large-scale operation in the 1950s due to a general lack of coal nationwide.

In the next stage of mining, 287 million tonnes of coal[3] would be extracted from the area beneath the towns of Černice and Horní Jiřetín and as far as the city limits of Litvínov, while the third and fourth stages would encompass the area under CheZa - Chemické závody or the large chemical plant in Záluží u Litvínova which houses Czech oil refinery operations – and terminate close to the city of Most.