The arch can be interpreted as the vault of the sky.
Various cultures link the arch to victory; Rome and France (L'Arc de Triomphe) being two of the most prominent.
Passing through an arch is the symbolic act of rebirth, of leaving the old behind and entering the new. They often mark access into holy places.
Adopted by the Muslims as an emblem of faith, it also has a link to heaven, sanctuary and a secret place.