The Basilica of BomJesus is the mainly august and famous of all the churches in Old Goa. It contains the ruins of St. Francis Xavier, Patron saint of Goa, Apostle of the Indies
The three storey structure is combination of Doric, Corinthian and Composite style of architecture from the exterior. It is built of black laterite stone.
The façade is divided into four parts. The lowest part contains three graceful entrances. The part above it has three large windows corresponding to the three entrances. The third section has three circular windows and the fourth part forms a quadrangle decorated lavishly with arabesque. All the sections are decorated with pillars and carvings on basalt brought from Bassein in north Goa.
The interior of church is made of Mosaic-Corinthian style and is noteworthy for its minimalism. Three rows of windows are raising one over another from each side besides those of the choir and corresponding circular ones. The windows in the second row have a protruding balcony skillfully attached to them. The entrance is beneath the choir and is supported by columns. The body of the Basilica is spacious.
The mausoleum is a three-tiered bier built by the Duke of Tuscany (1670-1737 AD) in return for the pillow on which the head of St. Francis Xavier rested for many years after his death.
The casket was constructed by Gaon silversmiths under the supervision of Fr Marco Mastrilli S.J. it is also known as Mastrillian casket.
The crystal urn was ordered after the exposition of D. Jose Costa Nunes, Patriarch of Goa in 1952, it was decided that the sacred relics should not be touched directly anymore. The crystal urn was made in the Casa Brandizzi at Rome and was brought to Goa on January 30th 1955. The relics were placed in the crystal urn first and then into the silver casket on February 13th 1955 and sealed. The old wooden coffin with its three keys is now kept in the museum at the Professed House of the Jesuits.