You can walk short distances on vertical surfaces.

Prerequisite(s): Dex15, Dodge, 6th-level Monk

Benefit: Each round, you may walk up to 10 ft. on a vertical surface, before landing on the ground again. This 10 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.