The Nervión River carried Bilbao's industrial fortune seaward for two centuries, and its transformation into a recreational waterway began only in 1983 when the old shipyards closed. Today the estuary route from Pantalan Pio Baroja traces 14 kilometres of repurposed docklands, passing beneath the Zubizuri footbridge's white arches and the rust-red span of La Salve beside the Guggenheim's titanium curves. The sunset boat tour Bilbao operators run follows the original cargo route, moving downstream past the remnants of crane infrastructure and nineteenth-century warehouses now converted into loft apartments and galleries. The journey reaches the Abra de Bilbao, the broad bay where the estuary meets the Cantabrian Sea, framed by the hills of Getxo to the north and the industrial port of Santurtzi to the south. The bay's sheltered water has anchored maritime activity since Roman times, when iron ore mined in the Basque interior was shipped from these shores. Modern Bilbao's prosperity began here in the 1870s when British engineers built blast furnaces along the riverbanks, and the estuary became a conveyor belt of steel and coal. Evening light softens the bay's working character, casting long shadows across the breakwater and the lighthouse at Punta Galea. The estuary's architectural signature is its succession of bridges, each marking a different industrial era. The Vizcaya Bridge, a UNESCO-listed transporter bridge from 1893, still ferries cars across the river mouth on a suspended gondola. Upstream, the modernist Pedro Arrupe footbridge and the cantilevered Deusto Bridge frame views of the old Abandoibarra docks, where Frank Gehry's museum rose in 1997 on the site of a demolished shipyard. The river's tidal range reaches three metres, and boat schedules follow the estuary's twice-daily rhythm. Departures align with high tide to ensure clearance beneath the lower spans. Bilbao's maritime identity has shifted from export hub to leisure corridor, but the estuary remains a working waterway. Container ships still navigate the channel to the inner port, and fishing boats dock at Santurtzi's quays. The sunset boat tour Bilbao route offers the clearest perspective on this layered history, moving through zones where nineteenth-century ironwork stands beside contemporary architecture, and where the city's industrial past meets its redeveloped present.