22. This Ancient, Expertly Made Wall
In the present-day city of Cusco, Peru stands an architectural marvel – a long-winding stone wall, with each stone weighing almost 100 to 200 tonnes! Built by the Inca Empire in the 14th-15th century, this is called the Sacsayhuaman wall. In fact, this wall was the setting of a fierce battle between the Spanish conquerors and the Incan natives.
But what’s baffling about this wall, you ask? Take a closer look at the precision with each stone is interlocked with the other – all done without using any binding agent like cement! The stones are so well locked in with each other that it’s impossible to even fit a sheet of paper between them. Pretty neat, eh?