There are. The thing is that they where not built upwards as most temples were, but downwards, into the earth and towards his realm. Most of the temples are built in or atop grottos associated to what are now called gates to Hades. Sometimes these are places where venomous or unbreathable gases rise to the surface. The sacrifices that where taken there died as through magic from asfixia while the priests survived, since these gases being heavier than air means they stay closer to the floors of the caves. Other time the caves "just" have other peculiarities, such as the no echo chamber I mention bellow. But the thing about caves and grottos is that the can collapse, and if the temple entrance is removed the knowledge of their existance can be lost and its not evident where they were located

Pausinias writes that the Pylus where the only ones that worshiped Hades, and that they opened his temple only once a year for "men too only go once to Hades". The most famous (currently known) one is the Nekromanteion in Ephira or Epirus, where Hades had an Oracle in a curious cavern with little to no echo and from where Odysseus enters the underworld. Most of the actual temple, along with a nearby temple of Poseidon, was, as is common, repurposed for a christian church but the greek site was discovered in the 1960s

Another one of them can be found at the Eleusian complex, primarily dedicated to Persephone and Demeter nevertheless a grotto dedicated to Hades can be found here. There are a few others that are mentioned in literature but as far as i know have not been confirmed archaeologically. There are more outside of Greece proper but I think this answers your current question