A 30 foot high cylinder of granite with a cross section diameter of 20 feet shoots up from below you, knocking off any creatures expect you. calculate the fall damage for these creatures from 30 feet. this spell lasts until you dispel it. while it exists, as long as you can see it you can teleport up to the top as an action. it's size is huge. It has an AC of 18 and 50 Hits points. After it is reduced to 0 hit points it reduces to rubble. while the tower has more than 0 hit points you and only you can jump off and not take fall damage. after 5 rounds of existing if it has not been reduced to 0 hit points it will sink back into the ground.