Somewhere I saw a documentary where the historian was walking through the place as she explained its history and construction. With context removed, it sounded like and appeared she was in a cathedral. Roman civil engineering never ceases to impress and amaze me.
When I was a kid, my uneducated, Italian immigrant uncles started 2 separate construction companies doing what they knew: one specialized in masonry and the other in concrete construction work. Both had municipal contracts and were very prosperous. They died before I was old enough to learn their methods, ask questions and listen to their stories. Seeing places like this makes me wonder how much of it was handed down over the centuries and I am sad that it has been forgotten in my lifetime. Thanks for the share!

The capacity is 12,600 cubic metres (440,000 cu ft),[1] amounting, in other words, to 12.6 million litres (3.33 million US gallons) of water, or roughly the size of 5 Olympic-size swimming pools.

Amazing. And yet that civilization still collapsed. Beware.