This study aims to analyze the architecture and its ornament of the old mosque in in Ulee Kareng – Banda Aceh. This old mosque is also known as the Masjid Tuha Ie Masen or Masjid Tuha Ulee Kareng. This study uses a qualitative approach through the descriptive analysis method. The research findings show that the shape of the Tuha Ie Masen Mosque building has undergone a change from its original form. There are several parts that have been renovated, including the roof, floors, and walls. The architectural form of the Tuha Ie Masen Ulee Kareng Mosque tends to be the same as that of old mosques in Indonesia. Archaeologically, the architectural form of the Tuha Ie Masen Mosque has similarities with the Tengku di Anjong Mosque and the Indr...