Guoliang Tunnel, Taihang Mountains, China
In 1972, inhabitants of a remote mountain village performed one of the most miraculous feats in road-building history: They chiseled a tunnel three-quarters of a mile through a mountain for easier access to the outside world. Here, "easier" means easier than tiptoeing along a rocky footpath worn into the face of the mountain, which is what they had to do before they built the tunnel.
But the new passageway, whose name translates to "road that does not tolerate any mistakes," is only marginally less hair-raising. The tunnel's 15-foot (4.5-meters) high ceiling and 12-foot (3.5-meter) wide roadbed would be forbiddingly dark and claustrophobic had the builders not also carved periodic openings in the tunnel walls. The resulting view of the gaping abyss just a few feet away from your wheels is enough to make you forget all about how confined you are [source: Travel + Leisure].