It is built on a small elevation, on the right side of the bed of the Havga River, across from Agios Konstantinos. It had 9 residents (as of 2001) and is located 57.9 km from Heraklion and 40.9 km from Agios Nikolaos.

The Monastery of Krustallenia is the religious center of the Lasithi Plateau and serves as the gathering place for the locals when they need to discuss matters of broader interest.

The exact founding date of the monastery is unknown. Some literary sources suggest that the monastery existed in the 13th century, which would place its founding in the Second Byzantine period. Unfortunately, these sources are not confirmed by other references, and thus the dating based on them remains uncertain.

The second dating is based on the fact that during the distribution of lands in Lasithi to Peloponnesian refugees in 1543, among the beneficiaries were the sisters Theokliti and Palantia Danasi. They were tasked with the obligation to establish two monasteries in Lasithi.

The monasteries of Agia Marina and the Virgin Mary were the ones to be established by the sisters. It is known that Theokliti founded the Monastery of Agia Pelagia in Alexaina. It is also certain that Palantia founded the Monastery of the Virgin Mary, or possibly renovated an older one. Since 40 years later, the land grant was still valid, it is highly likely that the monastery Palantia founded is the Monastery of Krustallenia. As a result, the Monastery of Krustallenia would have been established in the mid-16th century.
This view is supported by the presence of an architectural element in the monastery. Specifically, there is a stone-carved iconostasis window that was previously located in the skylight of the Sanctuary. It was removed before the war during the renovation work of the church, in order to facilitate the ventilation of the Holy Sanctuary. Today, parts of the old stone carving can still be seen in its original location, along with its base, which is preserved in the monastery.

This stone carving features exactly the same themes, is of the same meticulous craftsmanship, and has the same dimensions as the one still in place in the church of Panatassas in Avdou. It is evident that both of these works were created by the same artisan. Since the construction date of the Panatassas church is known to be 1600 AD, we can easily argue that the Church of Krustallenia was also built around the same time.

The monastery played a significant role in all the events during the period of Ottoman rule. It supported the group of Haiduks (Cretan rebels) led by Kazanomanolis, who had their hideout in Aloida, near its property at the Monastery of the Holy Apostles. It was the central meeting point for the local captains, and the abbots participated in meetings to make decisions and were members of local delegations in pan-Cretan or regional assemblies.

In Krustallenia, foreign travelers and visitors often ended up and were hosted, such as Siber in 1817, who was told by the older monks that no European or Frank had reached Lasithi in the last 27 years, that is, since 1790. Fabreguettes in 1834, who found that the monks had not managed to repair even some of the damages caused by Hassan Pasha in 1823, and Raulin in 1845, etc.

Not only foreigners, but also official Greeks were hosted at the monastery: Prince George, the High Commissioner, in February 1903, and Eleftherios Venizelos later the same year.

During the 1821 Revolution, the monastery was looted and subsequently set on fire and destroyed by the Turkish-Egyptian forces in January 1823. During the Great Revolution of 1866-69, Krustallenia played a leading role, as it served as the headquarters of the Revolutionary Committee of the Eastern provinces during the Battle of Lasithi (May 20-30, 1867). Here were stored the ammunition and supplies, and it was also home to the “gunpowder factory.”

During the period of the inter-Allied occupation of Crete (1897-98), a small detachment of French soldiers was stationed at Krustallenia to maintain order in the Plateau.

During the Cretan State period, Krustallenia, as a midway point on the route from Viannos to Neapolis (at that time, Viannos belonged to the Lasithi district), hosted the residents of Viannos who were traveling to the district capital to handle their affairs.

After the confiscation of 2/5 of the monasteries’ property to support the reserve funds, there was consideration of utilizing the monastery for tourism. Plans had even been prepared for this purpose, but ultimately, they did not proceed. During the period 1940-44, the monastery once again became a center of national resistance, and later, in February 1943, it was turned by the occupiers into a concentration camp.

Today, the monastery is striving to adapt to the new environment and the new circumstances, always within the framework of Orthodox monasticism.

An important activity that was successfully carried out in the monastery in the past was the regular operation of a school on its premises, from the mid-19th century until 1926.

The contribution of Krustallenia was significant in the religious, social, and national spheres. In this remote corner of Crete, in the inaccessible mountains of Lasithi, Krustallenia kept alive the national consciousness, the concept of social solidarity, and the flame of faith, laying the foundations for the rebirth of the nation.