This bridge is the path between Route 5 and Driftveil City, and it is the place for farming the Wings. These Wings raise an EV they describe by 1 EV, like a weaker vitamin. However, unlike the vitamins, these work until you reach 255 EVs in a stat, while Vitamins only work until 100 EVs have been reached for that stat. Alternatively, you can get Pretty Wings, which do absolutely nothing except be sold.
The alternate name for this bridge is Charizard Bridge, and you can sometimes hear the cry of a Charizard on this bridge. This is told to you by a little boy on the bridge, and, at the after game, you show him a Charizard, he gives you a Heal Powder.
On this bridge you can find Ducklett when on the search for Wings. These are the Water and Flying Pokémon in this generation, and they are not really that spectacular. While Pokémon like Gyarados and Mantine use this for offense and defense, respectively, Ducklett (and its evolution, Swanna) does not use the type to its advantage. It is oddly similar to Pelipper from Ruby and Sapphire, sharing typing, movepool, and usefulness. Swanna does have good speed, but not much else is going for it.