The Vidraru arch dam on the bank of the Argeş River in Romania is an engineering jewel. Built in 1966 to create hydroelectricity, it was the fifth largest dam in Europe at the time. It required 42 kilometers of tunnels, over a million hard rocks extracted from underground and nearly a million cubic meters of concrete to build, plus the loss of about 80 builders' lives.

The vast dam is itself worth a visit, and those who do will also catch a glimpse of a statue of Prometheus watching over the dam from atop Pleșa Mountain, holding a flash of lightning in his hand to symbolize electricity. The ancient Titan—who in Greek mythology stole fire from Mount Olympus and gave it to humans—looks like a modern-day superhero backdropped by the Frunţii Mountains and Ghiţu mountains that surround Lake Vidraru.

There's something hiding in these hills, too. The Vidraru dam was designed with an ingenious safety measure. To avoid nearby cities being flooded from a crack in the dam (from a bomb or otherwise), dynamite was placed strategically in the surrounding mountains. In the event that the dam breaks, the dynamite would be detonated and form a substitute dam out of the rock blasted out of the mountains.