Calbiga, officially the Municipality of Calbiga, is a municipality in the province of Samar, Philippines. According to the 2020 census, it has …Calbiga, officially the Municipality of Calbiga, is a municipality in the province of Samar, Philippines. According to the 2020 census, it has a population of 23,310 people. The town is famous for the Langun-Gobingob Caves which is the largest cave system in the Philippines, reputed to be the second largest in Asia and the world's third largest karst formation.