You can walk Greater distances on vertical surfaces.

Prerequisite(s): Dex15, Dodge, Vertical Walk, 11th-level Monk

Benefit: Each round, you may walk up to 30 ft. on a vertical surface, before landing on the ground again. This 30 ft. may be horizontal or vertical, so long as you do not exceed your base movement for the round. Moving across a vertical surface provokes an attack of opportunity, just as any horizontal surface does.