From WoWWiki
Corin's Crossing[55, 64] used to be a fairly prosperous crossroads trading town. Surrounded by the farmlands of
Lordaeron and located strategically at a crossroads connecting
Andorhal,
Stratholme, and
Tyr's Hand, Corin's Crossing was a common stop for traders and travelers. After the
Scourge turned the breadbasket of Lordaeron into the toxic
Plaguelands, Corin's Crossing has become an outpost of the Scourge. Travelers are advised to give the town a wide berth, as it is crawling with minions of the Scourge (levels 55+). Even rogues using stealth are advised not to attempt to sneak through the town, as there are
Unseen Servants present which are invisible and can detect other stealthed or invisible enemies.