LOS ANGELES—Archaeologists from the University of California, Los Angeles, and Ireland have discovered the world’s oldest leather shoe, an exquisitely preserved, 5,600-year-old woman’s size 7 lace-up, in a cave in Armenia.

The shoe, 1,000 years older than the great pyramid of Egypt and 400 years older than Stonehenge in the United Kingdom, was in such pristine condition that at first researchers thought it was just a few centuries old. It was stuffed with grass that may have been used to keep the wearer’s foot warm or that might have been to preserve the shoe’s shape for storage, the researchers reported Wednesday in the online journal PLoS One.

Both grass and shoe were well preserved, like other organic materials discovered in preliminary excavations of the cave on the border between Armenia and Iran, including winemaking apparatus complete with grapes and three human heads preserved in jars.

Most such materials degrade over time; the team attributed the unusual preservation to the cave’s perennially cool temperature and low humidity and a concrete-like layer of sheep dung that sealed everything in and prevented fungi from destroying the remains.

“The conditions in the cave . . . are rather rare,” allowing preservation of artifacts from a time period for which such materials are scarce, said UCLA archaeologist Charles Stanish, who was not involved in the research. The cave, he added, is only one of at least 39 that researchers are just beginning to explore.

“The potential to rewrite the early history of northern Mesopotamia is quite vast,” he said.

“The shoe itself is really interesting and cool,” added archaeologist Mitchell S. Rothman of Widener University in Chester, Penn., who was not involved in the research. “But it is just a marker of how incredibly good the preservation is at the site, which is incredibly important.”

The artifacts date from the Chalcolithic or Copper Age, when the first metal tools began appearing. “The fourth millennium is when the modern world appears — the first cities, the first kings, the first axes, the first bureaucrats, and the first international trading system,” Rothman said. Southern Iraq, where the first cities appeared, had no natural resources of its own and all the raw materials had to come from the surrounding mountains, from sites like this one.

The site “connects us up to this growing picture of the development of societies,” he said.

The new paper focuses primarily on the shoe, however. Prior to the discovery, the oldest known footwear from Eurasia was found on Otzi, the Iceman discovered on a glacier in the Otztal Alps on the border between Austria and Italy. Those shoes are about 5,300 years old, but were in relatively poor shape. They were moccasin-type footwear in which the sole is attached to an upper “sock” with leather thongs.

The oldest known footwear — more sandal than shoe — were discovered in Missouri and are about 6,900 years old. Made from woven fibers and leather, they are also in poor condition.

Radiocarbon dating indicated that the newly found shoe was from about 3,600 B.C. Its relatively sophisticated design, however, suggests that the style had already been in use for a long period, said UCLA archaeologist Gregory Areshian, the co-leader of the research team.

Previously, he added, researchers had tried to reconstruct what shoes had looked like from impressions on pottery and other fragmentary artifacts. “Here we have it in an absolutely tangible way.”

The shoe is shaped to fit the wearer’s right foot. It is 9.65 inches long, which corresponds to a U.S. woman’s size 7. Though small, it could easily have fitted a man from that era, said archaeologist Ron Pinhasi of University College Cork in Ireland, Areshian’s co-leader.

Researchers have so far excavated only about 2 per cent of the cave, which is at least 150 feet deep. They already know that the main part of the cave was not used for living, but primarily for storage and, perhaps, ritualistic purposes. The inhabitants apparently lived under rock shelters outside the caves.

The team believes the cave was abandoned following an earthquake, which caused the ceiling to collapse. After that, “it was used by pastoralists who grazed their sheep there” until about the 12th Century AD, when there is evidence of bread baking and other uses, Areshian said.

The research was funded by the National Geographic Society, UCLA and several foundations.