The West Bridge is the bridge that leads up to Dracula's Castle. At the beginning of the bridge are some blocks that can be broken with Holy Water or Dracula's Nail. However, they will not break unless all of Dracula's Relics and the Magic Cross are in Simon's possession.
The relics that you must possess are Dracula's Rib (Berkeley Mansion), Dracula's Heart (Rover Mansion), Dracula's Eyeball (Brahm's Mansion, Dracula's Nail (Bodley Mansion) and Dracula's Ring (Laruba Mansion). The Cross is obtained by defeating Vampira in Laruba Mansion.
Once these items are obtained and the blocks are broken, the bridge is itself devoid of enemies and leads to the abandoned ruins of the castle.