10.) Great Wall of China
Built over two millennia and reaching across more than 4,000 miles of mountainous terrain, the Great Wall is one of mankind’s most ambitious and long-winded construction projects. Aimed at keeping out foreigners, the Wall now attracts them from all over for a windy, brick-laden photo op.
9.) Taj Mahal
Started in 1631 by Shah Jahan, the Taj is one of the world’s most beloved landmarks and a testament to a (very wealthy) ruler’s love for his wife. Taking two years, 20,000 workers, and 1,000 material-hauling elephants to complete, the striking tomb and 42-acre grounds in Agra is considered the jewel of India.
8.) Millau Viaduct
Spanning the valley of the river Tarn, this cable-stayed bridge is nearly 2,500 meters long and 343 meters high, this Fosters + Partners project took three years to complete a cost of nearly €400 million. Seven reinforced concrete pylons hold up the iconic structure, which has won several awards.
7.) Hagia Sophia
The largest cathedral in the world for over 1,000 years, this former Byzantine mosque and church was one of the first experiments in indirect load transfers, boasting stacked domes that culminate in a main dome rising more than 183 feet into the air and spanning more than 100 feet wide.
This engineering marvel could house up to 50,000 blood-thirsty patrons, standing 157 feet high, 620 feet long, and stretching more than 510 feet wide. The entire stadium could be filled with water to simulate mock naval battles – and wash the blood of slaves, religious foreigners and prisoners.
5.) Channel Tunnel
Stretching more than 30 kilometers under the Channel waters separating England and France, the Chunnel provides high-speed train access between the two countries, taking 6 years to build at a cost of nearly 4.6 billion pounds. The five foot thick concrete tubes are buried an average of 150 feet below the sea bed.
4.) Three Gorges Dam
The world’s largest power station with a capacity of 21,000 MW, this concrete dam is 2,335 meters long and rises 185 meters above sea level. Crews moved more than 100 million cubic meters of earth for the massive project, which, upon its completion in 2008, totaled more than $22 billion.
3.) Giza Pyramids
The Giza Necropolis consists of three massive pyramids, the 240 foot long Sphinx statue, and several smaller cemeteries. The Great Pyramid of Giza consists of over 2.3 million limestone blocks and is over 146 meters high, making it the tallest human structure for over 3,800 years.
2.) Burj Khalifa
Officially the world’s tallest structure, this massive skyscraper in Dubai is nearly 830 meters high and cost $1.5 billion to build. Over 330,000 cubic meters of reinforced concrete was used in its construction, along with 55,000 tons of steel rebar and nearly 22 million man-hours.
1.) Panama Canal
The main shipping artery in the Western Hemisphere, the Panama Canal allows freighters to cross from the Atlantic to the Pacific Ocean in a mere 8-10 hours – though construction of the 50-mile corridor that took nearly 33 years to complete. After a failed eight year attempt by the French, the United States took the project through to completion despite heavy human losses – tens of thousands died from Malaria, other diseases, landslides, etc.
Today, the canal is one of the busiest in the world, giving passage to more than 15,000 vessels a year. The third set of locks project, aimed at modernizing the canal and enabling use for the world’s largest container ships, will more than double the Canal’s capacity upon its completion in 2014.