Center S (Центр С in Cyrillic script) was a secret, joint, Russian–Syrian signals intelligence post near al-Harra in southwestern Syria close to the Israeli-occupied Golan Heights.

[1] Presumably existing since before 2006, it was over-run by Free Syrian Army rebels on 5 October 2014 during the Daraa offensive.

The Center was operated on a joint Russian-Syrian basis, with Syrian Intelligence and the OSNAZ unit of the Russian GRU monitoring signals intelligence from Syrian rebels, as well as the Israel Defense Forces.

[2][3][4][5] On October 5, 2014, the Center was overrun by rebels affiliated with the Free Syrian Army in the Daraa offensive.

At least two other Russian intelligence centers are assumed to be located inside Syria.