Back from Peru

I took a month off and went to Peru with My family for the month of Jan. We checked out some amazing Inca and pre-Inca ruins. One thing we came across that was amazing from an engineering stand point was an aqueduct system that was cut from solid stone using a harder stone. These aqueducts were nearly 8km in length and they used ingenious designs like throwing a 90 degree angle in the path to lower the water level and slow the flow. They used system like narrowing or splitting the aqueduct to raise the water to transfer the water to a higher location. This amazing system in Andes took water and split it so one water way went left and moved water to the east which eventually dumped into the Atlantic and the other moved it to the right which eventually went to Pacific. Amazing engineering feat some 3500+ years ago, even before steel was discovered.