The Great Hall of Goeria
Despite having a length of nearly 2.0 kilometers, the Great Hall of Goeria was only recently discovered in 2150. Goeria is a vast open hall, 750 meters wide at the widest with an overall oval shape, held up by two rows of natural pillars. In the center is the Central Pillar, a huge column now covered in bolted on housing units often consisting of nothing more than modified cargo containers. At the north end of Goeria is a gigantic pit 250 meters across and estimated to be nearly 1km deep. It is filled with surface blown sand and detritus: nevertheless, the site is a major focus for tourists.
Just above the pit was a small opening to the Martian atmosphere as the Pit was once part of a natural sink hole. Soil and debris cover so much of the opening that it went unnoticed until some explorers fell through to the cavern below.
Very recently, in September 2158 Goeria was connected directly to the rest of Pharoah by way of a subterranean tunnel through which rovers can travel. The entire Hall is now pressurized as a dome was installed over the sinkhole entrance and air locks were placed at all surface entrances.