Strictly, the Hounfor is the inner sanctuary or altar-room of a site where the religion of Voodoo, Voudoo or Voodun is practiced.

In a more general sense, it is usually assumed to cover the entire site: the inner sanctuary, the peristyle, the dwelling of the houngan and probably some sacred trees, cairns or other landmarks including the bassin, for when water Loa are invoked during a ritual.

The main gateway to a hounfor is frequently denoted by two trees sacred to Legba.