The difference between tall and high bridges can be explained in part because some of the highest bridges span the deepest part of their valley or gorge supported from above, with their ground supports built on relatively high terrain only; some of the tallest bridges have support structures on the lowest part of the valley floor. For example, the
Huajiang Canyon Bridge is the highest bridge in the world, but not the tallest. This bridge spans a deep river gorge. The bridge's two towers, built on the rims of the gorge, are and tall, but due to the depth of the river gorge between the towers, the deck height of the Huajiang Canyon Bridge is . The
Millau Viaduct is a cable-stayed bridge that is both tall (in structural height) and high (in deck height). The tallest Millau Viaduct tower is situated near the valley floor, which gives the viaduct a structural height of , and a deck height of above the valley floor. The
Changtai Yangtze River Bridge is the tallest bridge structure in the world with a height of 352 meters (1,155 ft) when it was opened in Sept. 2025. ==Completed bridges==