Ancient Impossible

When faced with impossible situations, the ancients didn't simply give up, they pursued the impossible. How did they get troops across a nearly 4,000 foot river? How do you get oil from the ground without the use of modern drilling techniques? And how did they build a water tank which contained 3 million cubic feet of water, enough to provide for an entire city? What ingenious techniques did Caesar use to assemble a bridge to cross the Rhine, in only 10 days? The ancients created incredible structures to overcome these obstacles, often taking on and beating nature, using engineering methods that seem more modern than you would imagine.