The Holy Trinity Monastery (also known as Agia Triada, Ayías Triádhos, Ayia Triada; all meaning "Holy Trinity") 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). The church was constructed between the fourteenth and fifteenth centuries and is included in the UNESCO list of World Heritage Sites titled Meteora.
Dometius was said to be the first monk at the site of Holy Trinity, arriving according to local legend, in 1438. Holy Trinity according to many sources was built in 1475-76, though some sources say the construction dates of the monastery and its adjoining chapel, dedicated to St. John the Baptist, are unknown. Holy Trinity's decoration was added in 1741.
The church plan is in the form of a cruciform type and has a dome which is supported on two columns. The monastery’s main cathedral was constructed in the 15th century and decorated with frescoes in 1741 by two monks. A pseudo-trefoil window is part of the apse. There are white columns and arches, as well as rose-coloured tiles. A small skeuophylakion adjoining the church was built in 1684. Its broad esonarthex barrel vault was built in 1689 and embellished in 1692. The small chapel of St. John the Baptist, carved into the rock, contains frescoes from the seventeenth century. It was richly decorated and had precious manuscripts; however, these treasures were looted during World War II, when it was occupied by the Germans. The building's sixteenth-century frescoes are reported to be post-Byzantine paintings. A fresco of St Sisois and the skeleton of Alexander the Great adorns the walls.
Source: wikipedia.org