The only known British-made iron bridge in the United States, this modest structure is a segment of a larger bridge which once spanned the mouth of the Wailua River. Forming the outline of a slightly elongated equilateral triangle, the single-lane, Warren truss bridge is seventy-three feet in length with seven ten-foot panels, each nine feet, eight inches tall. The factory-riveted trusses with drilled, rather than punched, rivet holes, as well as the short height of the trusses and their resulting boxy shape, readily distinguish this British bridge from its American-made contemporaries. However, the end posts, deck, I-beams, and lateral braces are American, and date from the relocation of the bridge. The structure rests upon two lava-rock masonry abutments and a left-of-center, battered, lava-rock masonry pier.
Fabricated in 1890 by Alexander Findley and Company of Motherwell, Scotland, the Opaekaa bridge was one of three spans which comprised the Wailua River Bridge. Funding for the bridge was appropriated by the Kingdom of Hawaii's legislature of 1888, and the bridge was then ordered. Although delivered in a timely manner, an unstable economy, the result of the overthrow of Queen Liliuokalani in 1893, delayed erection of the bridge until 1894 or 1895. In 1919, when a concrete arch bridge replaced the 1890s Wailua River Bridge, this span was relocated to service the Wailua Homesteads' first series of homesteads, which opened in December 1919.