Were you looking for the Spirit Tower PvP objectives in the Bone Wastes?

Once infused with the restless spirits of the vengeful dead, spirit towers present a formidable defense. The wraiths of the tower attack with supernatural efficiency, and quickly add enemy forces to the ranks of dead. Multiple towers in an undead city will chill the heart of even the most courageous foe.^{WC3man 43} It is an upgraded form of the Ziggurat.

v • d • e Warcraft III: Reign of Chaos (Third War) buildings Human Alliance Town Hall · Farm · Barracks · Scout Tower · Guard Tower · Cannon Tower · Blacksmith · Lumber Mill · Workshop · Keep · Arcane Sanctum · Altar of Kings · Castle · Gryphon Aviary · Arcane Vault · Arcane Tower Orcish Horde Great Hall · Barracks · Burrow · War Mill · Stronghold · Altar of Storms · Beastiary · Spirit Lodge · Fortress · Watch Tower · Tauren Totem · Voodoo Lounge Undead Scourge Necropolis · Crypt · Graveyard · Ziggurat · Spirit Tower · Halls of the Dead · Temple of the Damned · Slaughterhouse · Altar of Darkness · Black Citadel · Boneyard · Sacrificial Pit · Haunted Gold Mine · Tomb of Relics · Nerubian Tower Night Elf Sentinels Tree of Life · Entangled Gold Mine · Moon Well · Ancient of War · Hunter's Hall · Ancient Protector · Tree of Ages · Ancient of Wind · Ancient of Lore · Altar of Elders · Tree of Eternity · Chimaera Roost · Ancient of Wonders