The twin brothers Cosmas and Damian were born in the Arabian Peninsula in the 3rd century AD, and lived in Asia Minor (now the teritory of Turkey).
They were called saints without money, because they practiced medicine and treated all people, poor or rich, without a fee.
They preached the Christian faith and suffered martyrdom in Syria.
They are venerated by both Catholics and Orthodox.
The 18th century wooden statues of Cosmas and Damian are placed in a display case in the church.
On 26th and 27th of September each year, a celebration of the Saints is held in town and pilgrims from the region travel the entire route by foot, as tradition dictates.

The Cathedral Basilica of Saints Cosmas and Damian (Parrocchia Santuario Basilica S. S. Cosma E Damiano).
Also called Basilica Santi Medici.
In 1609, a chapel dedicated to Our Lady of Grace existed in Alberobello; veneration of Saints Cosmas and Damian is attested from 1636.
Beginning in 1725, the church was expanded.
Between 1881 and 1885, the façade was rebuilt according to the design of the architect Antonio Currie, and then the rest of the church was renovated according to his design.
The parish church was declared a sanctuary on September 12, 1938, and in 2000, the church was granted the title of minor basilica.