The $n$-dimensional associahedron is a simple polytope with Catalan many vertices, corresponding to the triangulations of a convex $(n+ 3)$-gon, and $n(n+ 3)/2$ facets, in bijection with the diagonals of the $(n + 3)$-gon. In this talk I will describe the history of the Catalan numbers and the associahedron and describe some connections of this polytope to different areas of mathematics. I will also describe the toric variety of the associahedron. No specialized knowledge will be assumed.