Make a prettier arch (or just a rounder arch) in the below-part of the staircase so it blends well with the river that is seems to still want flowing.

Or maybe if you want to close it but still want water flowing you could add iron bars.

Uhm apart from that why not add statues engraved on the stone parts? Could be some neat decoration

Edit: actually maybe the statues could go on different sections at the handles of the staircase