Sandals are an open type of shoe, consisting of a sole held to the wearer's foot by straps going over the instep and around the ankle. Sandals can also have a heel. While the distinction between sandals and other types of footwear can sometimes be blurry (as in the case of huaraches—the woven leather footwear seen in Mexico, and peep-toe pumps), the common understanding is that a sandal leaves all or most of the foot exposed. People may choose to wear sandals for several reasons, among them comfort in warm weather, economy (sandals tend to require less material than shoes and are usually easier to construct), and as a fashion choice. Usually, people wear sandals in warmer climates or during warmer parts of the year in order to keep their feet cool and dry. The risk of developing athlete's foot is lower than with enclosed shoes, and the wearing of sandals may be part of the treatment regimen for such an infection. Although some other kinds of footwear like carbatina are as simple to make, sandals are the oldest known footwear at present. Pairs of sagebrush sandals discovered in 1938 at Fort Rock Cave in Oregon, USA, were later dated to 10,500 to 9,300 years ago.[3] The ancient Egyptians wore sandals made of palm leaves, papyrus,[4] and—at least in grave goods—gold. Egyptian statues and reliefs show sandals both on the feet and carried by sandal-bearers. According to Herodotus, papyrus footwear was part of the required dress of the Egyptian priests.[5] The sandals of Mesopotamia ("Biblical sandals") were typically made of rawhide and straw (dried grasses). The wealthy sometimes used gems or gold or silver beads on the thongs. Straw shoes, sometimes in the form of sandals and sometimes carbatinae, were ubiquitous Chinese footwear in antiquity. In Ancient Greece, sandalia proper were a kind of sandal principally worn by women.[6] The sole was made of wood, cork, or leather and the upper chiefly consisted of a strap between the big toe and second toe and another around the ankle.[6] The sandal of Homer was the pédila (πέδιλα).[7][8] By the Classical Period, the general term for sandals was hypódēma (ὑπόδημα).[8] Most forms included a strap across the toes (ζυγὸς, zygòs), another strap between the big and second toe, and a third across the instep (lingula); this last was frequently made with metal shaped like a heart or leaf.[8] The rhaḯdia (ῥαΐδια) extended the straps of the sandal up the calf.[8] Some Greek sandals—like the women's tyrrēniká (τυρρηνικά)—employed wooden soles.[8] The effeminate baxea (πάξεια, páxeia) was usually made of willow leaves, twigs, or fibers and was associated with comic actors and philosophers.[9] The tragedians wore the cothurnus (κόθορνος, kóthornos), sandal-like boots that rose above the midcalf and typically incorporated platform soles that led to others wearing them to appear taller.[10] By the Hellenistic Period, some sandals show evidence of extreme ornamentation. One found from the settlements in Greek Crimea was a platform design with 12 separate layers in its sole and gold decoration.