Metastability in Anti de Sitter Space

I discuss conceptual issues associated with the presence of metastable AdS vacua in the string landscape. The geometry of the decay from one AdS to another is presented in detail, and various subtleties that are not present for flat or dS vacua are demonstrated and analyzed. I use mostly semiclassical gravity, but I will consider the implications for recent attempts to construct field theory duals of metastable AdS vacua and also possible relevance to the study of eternal inflation.