On the east side of the main plaza is the 16th-century friary of San Gabriel, with its very large atrium, Capilla Real (Royal Chapel), Capilla de la Tercera Orden (Chapel of the Third Order), tall main church and Franciscan Library. Its cloister is still inhabited by about fifteen Franciscan friars. On the north side, there is the Parish of San Pedro, built in the 17th century. On another side of the plaza, one of the oldest residential structures in the Cholula area, called the Casa del Caballero Aguilar (House of the Eagle Knight) was converted into the Museo de la Ciudad de Cholula (Cholula City Museum). This museum was opened in September 2001, after a renovation project beginning in 1997 restored interior and exterior features such as stone sculptures as well as the original floor plan. The museum is a joint project of the city, INAH and the Universidad de las Americas Puebla. The museum traces the history of Cholula from about 1000 BCE through five rooms. The first three contain pre-Hispanic artifacts and the last two contain pieces and exhibitions related to the colonial period including religious art. The rooms also contain elements which recreate aspects of a colonial era home. The basis of the museum's collection is a group of about 1,500 artifacts from Omar Jimenez, from both the pre-Hispanic and colonial eras. There is also an area dedicated to photography of the city's religious festivals, and laboratories dedicated to the restoration of excavated objects.