The Mausolea. 2000. Places like these are where the dead are kept, frozen in liquid nitrogen, awaiting exhumation. They were built over many decades, hence the slightly different designs of these two examples. Most of them are near the poles, to reduce the power requirements for the cooling systems. These two are about 650 metres tall (about 2100 feet) and 1300 metres (about 4300 feet) along the base. They each house some 91 million dead on 160 levels.

The little huddle of buildings in the foreground is Serendipity Base, the location for much of the action in the first part of the story. Comments | Source