Portal at Voi

From Halopedia, the Halo wiki

The Cartographer Building[1] is a Forerunner installation in the African Savvanah of Earth, near the city of Voi.

It is the Forerunner artifact revealed in the Halo 3 E3 2006 Trailer. There is a tremendous "storm"[2] building over the desert near Voi, which is investigated by a Covenant Loyalist CCS-class Battlecruiser during the Second Battle of Earth. The UNSC military unit ONI Recon 111, that was assigned to shadow the battlecruiser, reports to Commander Miranda Keyes that the cruiser has "stopped...it's found something"[3]. The Covenant Loyalist fleet then makes a full-out assault on the structure, and at least two CCS-class Battlecruisers glass the African savvanah, uncovering the Cartographer Building[4]. The Forerunner Dreadnaught lands shortly afterwards and the Prophet of Truth debarks, entering the facility as the Covenant Loyalists place a large vehicular defense force to guard the installation, including a Scarab walker, and large numbers of Brute Choppers and Brute Prowlers.

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