A hoodoo is a weathered column of unusual shaped rock. Most of the hoodoos in Zion are comprised of a relatively soft column of sandstone, which is capped by a harder piece of stone. Although hoodoos can be found throughout much of the park, some of the most easily accessible ones are found along the Zion-Mount Carmel Highway.
The east side of Zion is at a much higher elevation than Zion Canyon, and the terrain is remarkably different. While the list of official attractions is short, there are a great many things to see and do on the east side of the park. Most of the area is covered in slickrock, and you can go off trail without damaging the area around you. Having said that, please keep in mind that the park specifically warns visitors not to trample on cryptobiotic soil. There's a display in the Visitor Center that helps you learn what to look out for.