Arena Bridge, a truss bridge was built in 1894 in Puerto Rico. Arena Bridge is the longest bridge in Puerto Rico during the Spanish period and crosses the longest river in Puerto Rico.

Metal required for the formation of bridge was scarce in Puerto Rico and hence metal was imported from France and Belgian firms. Mariano designed the bridge and this steel bridge weighs more than 20,000 pounds.

Arena Bridge was formed on 134 kilometer highway and the building of the bridge was completed in 1898. During the American-Spanish war many bridges in Spain were destructed but not Arena Bridge and at present Arena bridge is still in use and service.