This photo might be a stretch to share on an outdoor/hunting forum...sorry guys, but I'm a bit into history...
I took the above photo the other day near the port city of Terragona, Spain. The top, is an aqueduct channel built by the Romans over 2,000 years ago (40 BC), as part of a series of water transport systems to the port from an ancient river (now dry) over 15 km away. There has been a bit of cosmetic restoration, but it's been pretty much structurally intact. Those Romans sure knew and structurally applied the basics of physics...and longevity was also aided for this structure over the millennia because there was an apparent curse if someone molested or took stones from it.