Kaiadas is a deep cave just outside Trypi, on the road to Kalamata. Its entrance is about 30 metres above the road, and the cave goes down around 50 metres.
Legend says the Spartans threw weak babies here, but research tells another story: the bones found inside belong mainly to adult men. It is believed the cave was used to execute prisoners of war, traitors and criminals, mostly during the Messenian wars (8th–5th century BC). Today it is seen from the outside only.