"If you travel through Italy, you can’t help but notice the many Roman bridges that still stretch across that nation’s waterways. How is it that the Romans coul

"If you travel through Italy, you can’t help but notice the many Roman bridges that still stretch across that nation’s waterways. How is it that the Romans could build bridges that would last thousands of years, while the ones we build today collapse after a few decades?" You don't see bridges that have already collapsed thousands of years ago =)