True Sight

True Sight is a passive ability of Tower, Sentry Ward, Fountain, Necronomicon Warrior (level 3) and players who carry Gem of Truesight. It reveals any invisible unit in a nearby area, including Techie's mines, Observer Ward, and Sentry Ward.

True Sight has an AoE of 1100, although units in fog of war remain unseen by the Gem of Truesight carrier.