The Holy Monastery of the Transfiguration of the Savior, also known as Great Meteoron, stands as the largest and oldest monastery within the UNESCO World Heritage Site of Meteora. Established in the 14th century by Athanasios Meteoritis, also known as Athonitis, this male monastery originated with the construction of a temple dedicated to the Virgin Mary named Panagia is Meteoritissa Petra. Concurrently, Athanasios's disciple, Ioannis Uresis Palaiologos, took up residence at the monastery under the name Ioasaf, following in his mentor's footsteps. In 1387-1388, Ioasaf initiated the construction of a new, more modern temple to replace the original one.

Both Athanasios and Ioasaf are revered as saints, commemorated on April 20th. The monastery gained complete autonomy under the seal of Patriarch Jeremiah I, akin to the monastic institutions of Mount Athos. Adjacent to the monastery's entrance lies the brizon tower, which once housed the net mechanism, alongside the sanctuary's cellar (vagenarium), now serving as a museum. Further within, one finds the hearth, dining hall, hospital, and nursing home to the east, with the catholicon positioned to the right.

Constructed between 1544 and 1545, the catholicon, dedicated to the Transfiguration of the Savior, boasts frescoes attributed to the Macedonian school. Nearby stand the vaulted chapel of the Holy Forerunner and the chapel of Saints Constantine and Helen, erected in 1789. Above the monastery, one discovers the chapels of the Virgin Mary, Saint John the Baptist, the Holy Apostles, and Saint Nektarios.

The sacristy holds a collection of monks' skull fragments, believed to have belonged to those who once inhabited the monastery. The frescoes adorning the temple and narthex are likely the work of George, a disciple of Theophanos of Crete. Throughout history and into the present, Great Meteoron remains the primary hub of monastic life. Visitors, both then and now, are required to adhere to a dress code, with men prohibited from wearing sleeveless tops and shorts above the knee, while women are expected to wear long skirts below the knee.