The Mastabas Mosque, featuring its distinctive 9-dome architecture, stands as a true landmark in Rethymnon and has been granted to the Goulandris Natural History Museum (GNHM) by the Ministry of Culture. After completing the restoration process and relevant museological study, it began functioning as a Museum of Palaeontology, serving as an extension of the Goulandris National History Museum in Crete.

The paleontological collection belonging to the Municipality of Rethymnon forms the foundation of the exhibits and has already been transferred to the GNHM. This collection has been studied and preserved in collaboration with the University of Athens. Lifelike representations and anatomical arrangements of endemic mammals will be showcased in the exhibition. Visitors will learn about the dwarf Cretan elephants, dwarf hippopotamuses, and polymorphous Cretan deer, while also discovering information about these animals, the early inhabitants of Crete, and Greek mythology.

In the meticulously landscaped 250 sqm garden, a variety of trees and plants native to Crete have been planted, including plane trees, orange trees, olive trees, carob trees, Cretan palm trees, oleanders, and laurels, as well as shrubs like wild roses, lavender, dittany, rosemary, and more.

Currently, the Palaeontological Museum of Rethymno hosts a range of events, guided tours, educational programs, and activities for students, in addition to special tours for both Greek and international visitors.