[icanhackit]

I considered that as well. I live in an area of town where a lot of 110+ year old town houses still stand proudly (European cities would laugh at that statement) but I know that only the stuff built well is standing today while whatever had been made to a lower quality crumbled and was built over. Just because old buildings survive to this day doesn't mean everything from that era was built to last.

With regards to the featured article, I'd say multiple factors are at play - Roman concrete has amazing properties and structures that used it combined with good quality-control (i.e. correct material ratios in the concrete) and good engineering survived.

The human elements, quality-control and design, are less interesting than a magical substance.