It occurs in a variety of forms, from the Lombard band, which is a row of small arches that appear to support a roofline or course, to shallow blind arcading that is often a feature of English architecture and is seen in great variety at Ely Cathedral, to the open dwarf gallery, first used at Speyer Cathedral and widely adopted in Italy as seen on both Pisa Cathedral and its famous Leaning Tower. (en.wikipedia.org)
Lie facedown with your arms stretched out, in line with shoulders like a T. Float your arms up about 2 inches as you reach your head, neck, and shoulders forward and up into a very small arch. (mindbodygreen.com)
If you are bummed that you can't see the Natural Bridge because it has fallen, you can see several similar but smaller arches here. (earthtrekkers.com)