24-cell honeycomb honeycomb
In the geometry of hyperbolic 5-space, the 24-cell honeycomb honeycomb is one of five paracompact regular space-filling tessellations. It is called paracompact because it has infinite facets, whose vertices exist on 4-horospheres and converge to a single ideal point at infinity. With Schläfli symbol, it has three 24-cell honeycombs around each cell. It is dual to the 5-orthoplex honeycomb.