The Chapel of Saints Cosme and Damian ( Spanish : Capilla de San Cosme y San Damián ) was built because these two saints were commonly invoked during a time when New Spain suffered from the many diseases brought by the Conquistadors . The main altarpiece is Baroque , probably built in the 17th century . Oil paintings on wood contain scenes from physician saints , and are attributed to painter Sebastian Lopez Davalos , during the second half of the 17th century . The chapel contains one small altarpiece which came from the Franciscan church in Zinacantepec , to the west of Mexico City , and is dedicated to the birth of Jesus .