Callao Cave
Peñablanca, Cagayan
Callao Cave is perhaps one of the most popular caves in the Philippines (even more popular than the caves of Sagada) and the best known tourist attraction of the Cagayan Province. It is located in Barangays Parabba and Quibal, in the town of Peñablanca, a thirty minute drive from the provincial capitol Tuguegarao.
Unlike the caves of Sagada, Callao Cave is very easy to explore but requires little test of endurance as you go up the stair with close to 200 steps before witnessing the massive limestone and rock formations inside.
http://www.lakwatsero.com/destinations/callao-cave/
The Palaui Island at Sta.Ana Cagayan
Sta. Ana, the north-eastern tip of the province of Cagayan and mainland Luzon, is a Special Economic Zone bustling with some modern industrial establishments, casinos and other gaming facilities, it even has its own pelotary. The town is also blessed with beautiful coastline, with some great white sandy beaches along its shore. Yet it still looks so rural and laid back, projecting contrasting features that add to its mystique
http://www.lakwatsero.com/destinations/travel-guide-palaui-island/
Tuguegarao Cathedral
Aside from the famed Callao Cave and Cape Egaño in Palaui Island, Cagayan province is also known for its centuries-old brick churches. So, on my 3rd and final day in Tuguegarao City, I visited the Metropolitan Cathedral of Tuguegarao or the Saints Peter and Paul Cathedral. It is the seat of the Archdiocese of Tuguegarao and considered as the biggest Spanish-built church in the entire Cagayan Valley Region.
As stated on the National Historical Institute's marker, it was built from 1761 to 1767 under the supervision of the Spanish Dominicans who came to evangelize Cagayan Valley. The Diocese of Tuguegarao was established by Pope Pius X on December 6, 1911, it suffered massive destruction in WWII and was again rebuilt by Msgr. Bishop Constance Jurgens.
http://www.pinoyadventurista.com/2012/02/tuguegarao-cathedral.html
The Longest River (Cagayan River)
The Cagayan River, also known as the Rio Grande de Cagayan, is the longest and largest river in the Philippine Archipelago.[1] It is located in the Cagayan Valley region in northeastern part of Luzon island and traverses the provinces of Nueva Vizcaya, Quirino, Isabela and Cagayan.
The river's headwaters are at the Caraballo Mountains of the Central Luzon at an elevation of approximately 1,524 meters. The river flows north for some 505 kilometers[2] to its mouth at the Babuyan Channel near the town of Aparri, Cagayan. The river drops rapidly to 91 meters above sea level some 227 kilometers from the river mouth. Its principal tributaries are the Chico, Siffu, Mallig, Magat and Ilagan Rivers.
Magat River is the largest tributary with an estimated annual discharge of 9,808 million cubic meters. It lies in the southwestern portion of the basin, stretching approximately 150 kilometers from Nueva Vizcaya down to its confluence with Cagayan River about 55 kilometers from the river mouth.
Both Magat and Chico Rivers have extensive drainage areas which comprise about 1/3 of the whole basin.
The Ilagan River originates from the western slopes of the Sierra Madre and drains the eastern central portion of the Cagayan River basin with an estimated yearly discharge of 9,455 million cubic meters. It flows westward and joins the Cagayan River at Ilagan, Isabela, 200 kilometers from the mouth.
The Siffu-Mallig system lies on the slope of the Central Cordillera ranges flowing almost parallel to the Magat River. Marshes and swamps are found in some parts of its lower reaches.
Cagayan River and its tributaries have deposited sediments of Tertiary and Quaternary origin, mostly limestone sands and clays, throughout the relatively flat Cagayan Valley which is surrounded by the Cordillera Mountains in the west, Sierra Madre in the east and the Caraballo Mountains in the south.
The river has a drainage area of about 27,300 km². in the provinces of Apayao, Aurora, Cagayan, Ifugao, Isabela, Kalinga, Mountain Province, Nueva Vizcaya, and Quirino.
The estimated annual discharge is 53,943 million cubic meters with a groundwater reserve of 47,895 million cubic meters.
http://en.wikipedia.org/wiki/Cagayan_River
Magapit Suspension Bridge
The Magapit Bridge is suspension bridge that opened in 1978 to connect the east and west sides of the Cagayan River in the province of Cagayan. It is located in Magapit, Lal-lo, Cagayan. It is also known to be the first suspension bridge in Southeast Asia built during the Marcos Regime. The bridge was also named by the locals as the "Golden Gate of Cagayan". This bridge is one of the only two bridges in the province that runs across the mighty waterway of the Cagayan River.
http://en.wikipedia.org/wiki/Magapit_Suspension_Bridge
