Part of a gigantic, thousand-year-old structure that served as the largest hospital in the Middle East during the Crusader period will soon be open to the public, following a 13-year excavation, the Israel Antiquities Authority announced Monday.

Located in the Christian Quarter of the Old City of Jerusalem and owned by the Muslim Waqf (an Islamic endowment of property held in trust for charitable or religious purposes), the 11th-century structure spans more than 150,000 square feet and is characterized by massive pillars and ribbed vaults, with ceilings as high as 20 feet.

The Grand Bazaar Company of East Jerusalem initiated the excavation and research in cooperation with the Antiquities Authority. It plans to turn the structure into a restaurant and visitor center, expected to open to the public in the next year.

On Monday, the Antiquities Authority unveiled a main hall, which is similar in appearance to the Knights' Hall in Acre, in northern Israel, and is estimated to constitute only a small part of what functioned as a massive hospital.

Renee Forestany and Amit Re'em, the excavation directors from the Israel Antiquities Authority, say that the hospital served the entire population of Jerusalem, helping as many as 2,000 patients from all religions. In addition to the medical departments, the hospital also functioned as an orphanage.

In a press release, the archaeologists said, "We've learned about the hospital from contemporary historical documents, most of which are written in Latin. These mention a sophisticated hospital that is as large and as organized as a modern hospital."

The hospital was constructed by a Christian military order known as the Knights Hospitaller to provide medical treatment for pilgrims who came to Jerusalem to die. According to the archaeologists, the Muslim Arab population was instrumental in assisting the Crusaders in establishing the hospital and teaching them medicine. Saladin, founder of the Ayyubid dynasty, reportedly lived nearby and helped preserve the structure, allowing Crusader monks to stay there.

Remnants of horse and camel bones found during the excavation, as well as metal for shoeing the animals, indicate that the structure also served as a stable during the Middle Ages.

A 1457 earthquake around Jerusalem likely destroyed most of the building, which remained in ruins until the 19th century. Part of the building was opened as a market during the Ottoman Empire, and it served as a fruit and vegetable market until 2000, when excavations began.