SRD:Rod of Fortification

Fortification
This rod functions as a +3 light mace. In addition, it is useful for the construction and defense of fortifications. Whenever the wielder is benefiting from cover, the rod improves that to nine-tenths cover (+10 cover AC bonus and +4 cover Reflex save bonus; failure on the save results in half damage and success results in no damage). Three times per day, the rod can create food and water, as per the cleric spell, for twenty-four people. The rod also has the following powers:

Fortify: Four times per day, a stone wall can be created that is 12 inches thick, 10 feet high, and 30 feet long. This wall has a parapet and battlements across the top. (Alternatively, the power can be used to mend a broken existing wall. The gap to be filled can be no more than 300 square feet in area.) In addition, once per day, a great door of iron can be created that is set into one of the newly created walls. This door, 4 inches thick, may be a double door, a drawbridge, or a portcullis, as chosen by the wielder.

Siege Engine: One heavy catapult, two light catapults, or three ballistae may be generated with each use of this power. The power can be used four times per day. Ammunition for 20 shots is included with each weapon created.

Caster Level: 24th; Prerequisites: Craft Rod, Craft Epic Rod, Craft Magic Arms and Armor, interposing hand, create food and water, major creation, wall of iron, wall of stone; Market Price: 465,665 gp; Cost to Create: 231,985 gp + 14,634 XP.