The old Piasau bridge was a Bailey bridge at Piasau linking from the peninsular to Piasau at the point closest to the sea. The bridge, originally made of steel and wood with a single lane to handle the occasional vehicle traffic crossing, has seen several upgrades over the years.
The two storey solid wooden building housing the museum today was built in the year 1897 as a fort by the second White Rajah, Charles Brooke to impose peace and order in the region where warfare among the local tribes prevailed. The ground floor of the building was used as a jail and also a storage space during the Brooke rule. In 1985, the building was gazetted as an official monument. It was used for administrative purpose housing the Resident and the District office of the division and also other government departments before it was gazatted as a historical building.