Housed in the Old Presidencia (former city hall), designed in 1937 by noted Filipino architect Juan Arellano — the same architect behind Manila’s Old Legislative Building (now the National Museum of Fine Arts). Declared an Important Cultural Property in 2019, restored with a ₱50 million budget, and opened as the National Museum’s 14th regional branch on November 25, 2022. Free admission. Ground floor covers the natural history of Negros Island (geology, zoology, botany); upper areas cover archaeology, architectural heritage, and models of historic buildings from Dumaguete, Siquijor, and Bacong. Open Tuesday-Sunday, 9am-5pm, closed Mondays. Reviewers consistently highlight the knowledgeable guides and air-conditioned comfort. Tours can be arranged via the museum office.