Sport climbing is another form of free climbing. These climbs are protected exclusively with fixed protection-usually bolts and hangers. Sport climbs have developed rapidly at cliffs where there are few cracks for protecting climbs traditionally. Some cliffs consist entirely of sport climbs. Sport climbing is very popular because it is less expensive and easier to learn than gear-intensive traditional climbing. Because the protection is very solid and easy to use, sport climbing also has allowed climbers to push their limits on very difficult terrain with little fear of the repeated falls that often result.