The Holy Trinity Monastery is an Eastern Orthodox monastery in central Greece, situated in the Peneas Valley northeast of the town of Kalambaka. It is situated at the top of a rocky precipice over 400 metres high and forms part of 24 monasteries which were originally built at Meteora, one of the oldest still existing of the Meteora monasteries (Meteora means "suspended in the air" in Greek). Six of the 24 monasteries are still active and open to visitors.