Old Goa or Velha Goa (Velha means “old” in Portuguese) is a historical city in North Goa district in the Indian state of Goa. The city was constructed by the Bijapur Sultanate in the 15th century, and served as capital of Portuguese India from the 16th century until its abandonment in the 18th century due to a plague.

The place is known as Saibachem Goem (referring to St. Francis Xavier as Saib i.e. Master), Pornnem Goem, Adlem Goem or just Goem in Konkani.

The remains of the city are a UNESCO World Heritage Site. Old Goa is approximately 10 kilometres east of the state capital Panjim.

Alfonso Albuquerque – the founder of Goa – built the first church here, that of Our Lady of the Rosary. He also built the Se Cathedral, the largest church in Asia, that took 80 years to completed. The construction of Churches continued at a fast pace and eventually there were some 12 huge and magnificent churches and monuments roughly in an area of one square kilometre in Old Goa.

Some of the  holy places of are Se Cathedral ( the largest of the churches in Goa), Convent and Church of St Francis of Assisi, Basilica of Bom Jesus, and Church of St Cajetan, Church of St Augustine ruins and Church and Convent of St Monica.

Famous throughout the Roman Catholic world, the imposing Basilica of Bom Jesus contains the tomb and mortal remains of St Francis Xavier, the so-called Apostle of the Indies. St Francis Xavier’s missionary voyages throughout the East became legendary. His ‘incorrupt’ body is in the mausoleum to the right, in a glass-sided coffin amid a shower of gilt stars.

Source:

https://en.wikipedia.org/wiki/Old_Goa

http://holidaysgenius.com/5-most-beautiful-churches-in-goa/

http://www.goatourism.gov.in/destinations/churches/128-old-goa-heritage-site