  Suppose a one-dimensional isometry group acts on a space, we can consider a
submergion induced by the isometry, namely we obtain an orbit space by
identification of points on the orbit of the group action. We study the causal
structure of the orbit space for Anti-de Sitter space (AdS) explicitely. In the
case of AdS$_3$, we found a variety of black hole structure, and in the case of
AdS$_5$, we found a static four-dimensional black hole, and a spacetime which
has two-dimensional black hole as a submanifold.
