1. You may wonder if it was really possible to stage mock boat fights in the colosseum. Check out this PBS video explaining how this would have been made possible.
2. Another amazing engineering marvel of ancient times is Chand Baori. This is the deepest stepwell in the world. It contains 3,500 stairs to the bottom and they are laid out in a beautiful geometric way that still attracts tourists today. "Centuries ago, the stepwells were built in the arid zones of Rajasthan to provide water all year through."-
3. The Shushtar Hydraulic System in Iran is made up of incredible early engineering techniques. It consists of 13 dams, bridges, canals, and structures that work together as a hydraulic system. This site is now a Unesco World Heritage Site. This system made it possible to create a new town and farmland.
"Shushtar is a unique and exceptionally complete example of hydraulic techniques developed during ancient times to aid the occupation of semi-desert lands. By diverting a river flowing down the mountains, using large-scale civil engineering structures, and the creation of canals, it made possible multiple uses for the water across a vast territory: urban water supply, agricultural irrigation, fish farming, mills, transport, defense system, etc. It testifies to a technical culture dating back eighteen centuries serving the sustainable development of human society, in harmony with its natural and urban environment." - https://whc.unesco.org/en/list/1315/
4. Saqsaywamwan, in Peru, is the site of a magnificently constructed citadel of stone walls. What is so unique and mysterious about this engineered masterpiece is that the stones fit together so perfectly and no mortar is used to hold them together. The quarry where the giant rocks would have been excavated was miles away. It is unknown how the rocks were transported to the site.