Right across from the Great Meteoron Monastery is the Men's Holy Monastery of Varlaam, or All Saints. Constructed at the onset of the 16th century by the hieromonks Nektarios and Theofanis, descendants of the prominent and wealthy Byzantine family of Apsarades from Ioannina, the monastery has a rich history. It was initially inhabited in the first half of the 14th century by Varlaam, a contemporary of Saint Athanasios, the ascetic-retiree from Meteora, after whom the monastery is named.

In 1518, the Apsarades undertook renovations on the chapel of the Three Hierarchs, situated on the site of the original monastery's katholikon built by Varlaam. Subsequently, in 1541, they constructed the current katholikon, dedicated to All Saints. This katholikon, in the sanctuary, is a cruciform inscribed Athonite church. Additionally, in 1536, they erected the prison tower.

The chapel of the Three Hierarchs was rebuilt in 1627 on the previous site of the old catholicon constructed by the Apsarades, and in 1637, it was adorned with paintings by the artistic crew of priest Ioannis and his children, who hailed from Kalambaka. The iconography of the monastery's katholikon occurred in three phases. Initially, in 1548, the frescoes of the holy step and the main church were painted by the renowned iconographer Fragos Catalanos. Then, in 1566, the austerity was painted by the Theban hagiographers Georgios Kontaris and his brother Fragos, sponsored by Antonio Apsaras, the bishop of Vellas of Ioannina.

The final phase of decoration, witnessed by a foundational inscription on the northwestern pesso above the representation of the Virgin Mary, occurred around 1780 and 1782. However, the exact details of this phase remain unclear. The monk Christophoros made a significant contribution during the 18th century by cataloging the valuable archive of the monastery and copying a set of historical texts.

Adjacent to the katholikon lies the Holy Table, which houses relics, along with the chapel of the Three Hierarchs, the hearth, the cells, and the guest house. Towards the entrance, on the opposite side, are the hospital and the chapel of Saints Anargyroi. Visitors to the monastery are required to adhere to a dress code, with men asked not to wear sleeveless tops and shorts above the knee, and women to wear long skirts below the knee.