The Windward Viaducts are a pair of highway viaducts that pass along the edge of the KoâÂÂolau Range between the Tetsuo Harano Tunnels and the Hospital Rock Tunnels on the island of OâÂÂahu in the State of Hawaii. The viaducts are located on Interstate H-3, which connects Kaneohe with the Interstate H-1 and Interstate H-201 freeways at HÃÂlawa near Pearl Harbor. These structures are among the longest bridges in Hawaii and are considered an engineering marvel.