Hoodoos are formed by different rates of erosion between different rock types, the more slowly eroding rocks forming pillars. The famous Drumheller hoodoos have been previously featured on TravelGumbo, and they are very photogenic.
Not quite as dramatic in shape but set in an even more evocative landscape are these hoodoos in the Bow River Valley near Banff. The mountain in the background is Mt. Rundle.