Grand 120-cell

The Grand 120-cell is a four-dimensional convex polytope, which is one of the higher-dimensional analogs of three-dimensional shapes. It is part of a class of polytopes known as "regular polytopes" in four dimensions, specifically a type of "uniform 4-polytope". The Grand 120-cell is an extension of the 120-cell, one of the six regular convex 4-polytopes.