The Great Bridge

Towering above the waves, encrusted with barnacles, a bridge spans the sea, high enough for ships to sail under it, and long enough to disappear into the horizon in either direction. Once a great trade route, now, the tower outposts --stationed every twelve miles or so--are mostly abandoned. The only living evidence of its former grandeur are a few fishing villages built right on the bridge and scaffolded haphazardly onto its columns. They still cheerfully charge a petty toll to those who seek to cross. Inspiration I'm basically ripping this straight from One Piece, but it's a great idea!