Formerly dubbed as " La Montanosa" by Spanish administrators for its mountainous terrain, Mt. Province lies in the heart of the Grand Cordillera, known to be the Philippine's biggest and highest chain of mountains. The province is bounded on the North by Kalinga, on the south by Benguet and Ifugao, on the east by Isabela, and on the west by Ilocos Sur and Abra. Mt. Province's total land area is 2,239.9 square kilometers, 23% of which are classified as alienable and disposable, and 77% as forest lands. Towering peaks and sharp ridges describe the central and western parts of the province, while gradually sloping and rolling foothills are the general features of the eastern towns. Mt. Province is geo-politically subdivided into 10 municipalities and 144 barangays. As of May 2010, the total population of Mt. Province is 153,187 and a growth rate of 1.41 from 1990 to 2010. Agriculture is the main source of income with tourism providing a significant boost to its economy. Although Bontoc is the province's capital, the town of Sagada is more famous among tourists. Its rice terraces, though lesser known compared to the Banaue rice terraces, are equally spectacular. Whereas the walls of the Banaue's terraces are of compacted earth, Sagada's walls are small rocks laboriously piled one on top of the other. The town is also known for its limestone caves that served as burial grounds during the pre-Christian Sagada era. Mountain Province boasts of being the first province to be evangelized by the American missionaries and so most of its people particularly, the elders could speak English. Aplai is the major dialect. The inhabitants could also speak Ilocano and Filipino.