The Mona Island Tramway (Spanish: Tranvía de la Isla de Mona) was a 1.8 kilometres (1.1 mi) long narrow-gauge industrial railway with a gauge of 600 mm (1 ft 11+5⁄8 in) on Mona Island, part of the municipality of Mayaguez, Puerto Rico. It was laid in the 1890s to transport building materials from the beach to the construction site of the 16 meter (52 foot) high Mona Island Lighthouse, which was put into operation on 30 April 1900.