Ancient lake full of crop circles lurks in the shadow of Saudi Arabia's 'camel-hump' mountain — Earth from space

This intriguing astronaut photo shows an oasis town and crop circles lurking within the shadowy tail of a "camel-hump" mountain in the harsh Saudi Arabian desert. The unlikely settlement lies within an ancient lake bed and is home to rock art dating back thousands of years.

The town, known as Jubbah, is located around 415 miles (670 kilometers) northwest of Riyadh and is home to around 5,000 people. It lies at the heart of the hyperarid Nafud (also spelled Nefud) desert, but it has remained an agricultural hot spot for generations thanks to its plentiful supply of underground water. Today, most farming is focused around center-pivot irrigation, which creates circular fields of vegetation.

Jubbah sits within a bowl-like depression left over from an ancient lake, or paleolake, that measures around 12.5 miles (20 km) long and 2.5 miles (4 km) wide. As a result, parts of the town lie "hundreds of feet" below the surrounding sea of dunes, according to NASA's Earth Observatory.

At the western end of the paleolake stands a 4,144-foot-tall (1,264 meters) mountain, dubbed Jabal Umm Sinman (meaning "two camel-hump mountain"), due to "its resemblance to a camel with two humps resting on the ground" when viewed from ground level, according to Visit Saudi.

The prevailing winds in the area blow from west to east (left to right in the image), meaning Jabal Umm Sinman generates a "wind shadow" that largely shields Jubbah from sand being blown across the desert, according to the Earth Observatory.

Before the desertification of the Arabian Peninsula, Jubbah Lake was one of several freshwater sources in the region. Most of these sites had dried up by around 5,000 years ago. However, Jubbah Lake likely persisted longer thanks to its subsurface aquifer, which continues to supply the town's water.

This likely made the lake a popular landmark for prehistoric humans wandering through the desert, long before the town was established. If you look closely at the image, you can see a faint road (above Jubbah), which likely matches the path used by these early travelers, according to the Earth Observatory.

These people also left their mark in the foothills surrounding Jabal Umm Sinman by carving symbols and pictures in the rocks. In total, there are around 5,500 inscriptions and 2,000 animal depictions, including portrayals of ibex, leopards, ostriches, dogs on leashes, and more than 1,000 camels.

This extensive rock art dates back at least 10,000 years and is part of a UNESCO World Heritage Site, along with two other nearby sites near Shuwaymis.

Saudi Arabia is an archaeological hot spot for rock art and other Paleolithic structures. For example, Jubbah is around 155 miles (250 km) northeast of the famous Al Naslaa rock — a hefty sandstone slab covered in prehistoric carvings and mysteriously split into two perfect halves.

Recent research into 8,000-year-old giant "kite" structures in the region hints that the carvings may be the world's oldest megastructure blueprints.

See more Earth from space