The Great Wall of China

Although the addition of expensive materials, sculpture and landscaping can add to the expense of a renovation, these aren't the only ways to measure cost. A startling example is the Great Wall of China, one of the most ambitious building projects ever undertaken. Begun around 217 B.C. as a military fortification, the great wall has actually undergone three renovations and extensions to the original structure, and at its longest, stretched more than 4,000 miles (6,500 kilometers).

When it was finally abandoned after the advance of the Manchus in 1664, the Great Wall had witnessed the toil of countless souls working to extend and reinforce it over the course of almost 2,000 years, some almost certainly dying at their labor. There's even speculation that some of these unlucky workers were entombed in the wall itself