Guard of Suramar

The Guard of Suramar  (or the Suramar Guard, Suramar's Watch, or simply the Watch) was the night elf organization of troops who fought and defended the city of Suramar. Jarod Shadowsong rose to the rank of a captain by the time of the War of the Ancients. Jarod was later placed under the command of Kur'talos Ravencrest.

Suramar had only a small facility for prisoners, most of any import ending up in Black Rook Hold. The Guard's headquarters was created out of the base of a long dead tree. The roots formed the skeleton of the building and workers had created the rest from stone. There was no more solid a building than this save Lord Ravencrest's hold and the Suramar Guard were proud of that.

Speculation
Modern day Suramar is protected by the Duskwatch, which is likely what the Suramar Guard evolved into.