Google Maps users have been puzzled by a mysterious spiral shape that has appeared in the Egyptian desert near the shores of the Red Sea.

While it may look like the work of aliens or an ancient civilization, the curving configuration is actually a 1-million-square-foot environmental art installation constructed in March 1997, The Christian Science Monitor reported.

The art piece, which has two interlocking spirals, initially had a small lake at the center that has since emptied.

Called "Desert Breath," the installation was designed and built by artists Danae Stratou, Alexandra Stratou and Stella Constantinides.

"The project is rooted in our common desire to work in the desert," the artists said on their website. "In our mind's eye the desert was a place where one experiences infinity. We were addressing the desert as a state of mind, a landscape of the mind. The point of departure was the conical form, the natural formation of the sand as a material."

The giant art structure was built through the displacement of sand into cone-shaped hills and depressions, both of which are slowly yielding to the desert.

Knowing that the design will eventually no longer be part of the landscape is part of the point, according to the artists. The structure is "becoming through its slow disintegration, an instrument to measure the passage of time," the artists said on their website.

Other unusual shapes have sparked debate and later been revealed to be man-made.

In one example, a large pentagram in Kazakhstan was a mystery until people discovered that it was actually the outline of roads from a park in the Soviet era, according to The Christian Science Monitor.

See Now: OnePlus 6: How Different Will It Be From OnePlus 5?