The Amazon River has no bridges across its entire length

Despite stretching roughly 4,000 miles through South America, not a single bridge crosses the Amazon's main stem. Most of the river runs through dense, sparsely populated rainforest where there's little road traffic to justify one, and the river's width and shifting banks would make construction extraordinarily expensive. Where crossings are needed, people rely on ferries instead.

— Wikipedia contributors, Amazon River — Amazon basin infrastructure