The Municipality of Nabua traces the historical origin of its name way back during the Spanish Colonization. It was said that in 1571, an Augustinian Friar named Fray Alonzo Gimenez reached one of the rancherias called “Lupa” which was then under Datu Panga from Borneo. The good friar found persons inside the said rancheria cutting coconuts. He was offered to partake the inside shoot of coconut which the natives called “boa.” Immediately, Fray Alonzo tagged the place as “Nabua” pronounced with his Spanish Accent. From that time onward, this place become popularly known as “Nabua.”
In another version, a historian named Fray Felix Huerta claimed that the name came from the story that the original sitio of the town is in the shape a young coconut embryo which was surrounded by five rancherias named Lupa, Antacodos, Sabang, Caobnan, and Binoyoan. Other believed otherwise and said it was centrally located in the middle of said rancherias, thus closely resembling “boa.” For a time, the town was called “Nabobowa” but years of long usage shortened and corrupted it to the present name.

In 1578, a group of Franciscan missionaries led by Fray Pablo de Jesus and Fray Bartolome Ruiz put up a church in Antacodos where they placed a big cross. These missionaries soon merged the villages of Lupa, Antacodos, Sabang, and Binoyoan into one place.
In a research mission to Spain funded by the municipality, it was learned that Nabua was officially established as a municipality on July 25, 1569.
Based on the 1734 Murillo-Velarde map, one of the earliest cartographic maps of the Philippine archipelago, the town is identified as “Nava” – a Spanish name indicating a “level piece of ground.” This is probably the apt description of the place at that time, and until the present time, a flat terrain stretching from the shores of the lakes of Bato and Baao and nestled in the plains between Mt. Asog and the mountains of Bula and the then Pantao.

READ FULL DETAILS: http://en.wikipedia.org/wiki/Nabua