Opened across the Tagus in Lisbon in 1966, this was originally the Salazar Bridge. During the Carnation Revolution in 1974, the lettering was ripped off the bridge, and it was renamed to commemorate the date—which leads to the curious fact that the 25 April bridge opened on 6 August. The Lisbon half-marathon crosses the bridge each March.

It originally carried four road traffic lanes, later expanding to six lanes. To minimise aerodynamic forces, the cars in the two lanes in the centre of the deck drive on metal grating, which means that the bridge emits a distinctive hum.

The bridge’s original design also called for it to carry trains on a lower deck, but cost constraints meant that this element was dumped. It was subsequently un-dumped in 1999, when the original builders were brought back to re-engineer the bridge with a second deck after all.