Here are links to information about the many famous and historic cathedrals, churches and religious shrines located around the islands of the Philippines.

Cathedrals, Churches & Shrines

The first Catholic Mass was celebrated in Philippines at Limasawa Island near Padre Burgos, Southern Leyte in the central Visayan islands group in 1521.   The island has great snorkelling.  It is also a pleasant climb up the steps to the Cross from which there are some views of the sea:

http://www.tripadvisor.com.au/Attract...

http://newsinfo.inquirer.net/379995/c...

 The most populous island of Luzon has many historic Catholic Churches in not just Manila (such as San Agustin in Intramuros) but in areas such as Central Luzon and further north in Ilocos Sur and Ilocos Norte.  The Visayas island of Panay has a large number of beautiful Churches in not only Iloilo City but towns such as Anin-y, Guimbal, Leon and Mia-gao.  

The home of Christendom in Asia is the Minor Basilica of Sr. Santo Nino in Cebu City, Visayas near Magellan's Cross and not far from Fort San Pedro.  The Basilica is a must visit and stunningly beautiful inside.