The covariant phase technique is used to compute the constraint algebra of
the four-dimensional space-times which are asymptotic to anti-de Sitter (Ad
S), such as the planar Taub-NUT AdS and Taub-bolt AdS spaces, and the hyper
bolic Taub-bolt AdS space. The standard Virasoro subalgebrae with correspon
ding central charges for these objects are constructed and the resulting de
nsities of states yield the expected Bekenstein-Hawking entropies.