What is it that makes the icelandic horse so special?

Flying pace

The icelandic horse is the only naturally five-gated horse in the world! Not all of them are five-gaited, some of them are four-gaited. They have the three basic gaits: walk, trot, and, canter. They have two more gaits, tölt and flying pace. A four-gaited horse does not do the flying pace. 

Tölt

Tölt is a regular four-beat movement which resembles a rack. It can be performed at different speeds, varying from a slow tölt, a bit faster than a walk, medium tölt, which compares in speed to a medium trot, and fast tölt, as fast a medium canter. Flying pace is ridden at very high speeds and only over short distances, with both the legs on the same side of the horse touching down at the same time.

The tölt, the most pleasurable gait, is free flowing and effortless, allowing the horse to cover rough terrain swiftly. Many Icelandic Horses also pace, an exhilarating racing gait which can be performed at speeds up to 30 miles per hour.