Great Wall of China

1. Great Wall of China, China

Behold! The Great Wall of China. So why does it snag top spot? I mean, we've all seen a wall before, and it's not even the oldest of the World Wonders. Well, this is no ordinary wall. It's a formidable fortress, spanning almost for infinity, as wide as the Chinese history is long.

Strictly, it's 13,000 miles/21,000 kilometers. Let's think about that for a minute. The 2 capital cities furthest apart in the world are London and Auckland - they are still only 11,690 miles apart. For those who are not familiar with the location of those cities, then it's 90,943,478 chopsticks in length, but I tend to think that's harder to imagine. Wow, my mind is completely blown! So this is reason one.

Secondly, it is a marvel of engineering. What you may not appreciate unless you visit is, the Great Wall is not flat. Sections of it meander through mountains, with very steep inclined steps. To build in such locations is mindboggling, and having been out of breath climbing these, I can only imagine how the soldiers protecting against nomadic tribes would have felt, climbing up and down all day in full body armour, sometimes under the baking sun!