Palak
The method by which the ancient Nazca people created these vast, precise geoglyphs without aerial views is still debated.
The transport and arrangement of Stonehenge's massive stones, originating from distant quarries around 3000 BCE, remain a mystery in terms of methods and purpose.
How the Tiwanaku people carved hard andesite stone with such precision, lacking a written language, advanced metallurgy, and using only stone tools, is unknown.
Unlike other ancient cities, Çatalhöyük, built between 7100 and 5700 BCE, predates farming, writing, wheels, and metals. The activities of its inhabitants remain unclear.
The Paracas Candelabra, a giant geoglyph etched into the northern face of the Paracas Peninsula and visible from afar at sea, has an unknown purpose.
Dating to around 9600 BCE, Göbekli Tepe predates Stonehenge by millennia. The reasons and methods behind its construction by hunter-gatherer societies are baffling.