Four major bridges connect the various elements of the Arkansas River Trail and allow easy crossings to explore different areas. Dedicated on September 20, 2006, the Big Dam Bridge is the longest pedestrian and bicycle bridge in the world designed and built for that purpose; its 4,226-foot length rises to a peak of 90 feet above the Arkansas River, is 14 feet wide, and includes eight observation areas with benches. Because the Murray Lock and Dam was not designed to include a pedestrian and bicycle crossing, the Big Dam Bridge was created as a modification of it, and the large concrete monoliths nearby are cut-outs from the base of the Murray Lock and Dock structure made to provide space for the bridge footing, with each monolith weighing about 3 tons. Junction Bridge spans the Arkansas River between Little Rock's Riverfest Amphitheater in the River Market District and Verizon Arena in North Little Rock, provides views from atop its 360-foot lift span 40 feet above the river, is 17 feet wide, and serves as the fifth component of the Six Bridges Plan with elevators, benches, and trash cans. Originally constructed in 1899 by the Choctaw and Memphis Railroad and operated by the Union Pacific Railroad, it carried trains across the Arkansas River until its active railroad use ended in 1984. The Clinton Presidential Park Bridge, a 1,600-foot former railroad bridge, overlooks the 13-acre William E. "Bill" Clark Wetlands, features specially designed aluminum flower boxes along its side, and marks the beginning of Arkansas River Trail System measurement. The 1,162-foot Two Rivers Park Bridge, also known as "the promenade in the sky," connects River Mountain Park and Two Rivers Park, has LED fixtures capable of creating millions of color combinations, and attracts hundreds of thousands of visitors each year.