Where: Originally located in Giza, part of modern-day Cairo, Egypt.

Why: A tomb constructed by Egyptian Pharoah Khufu in 2560 B.C.

Wonder: The great pyramid of Giza remained the tallest structure on Earth for more than 4,000 years. The pyramid is believed to have been built over two decades period, which includes its architectural planning and the placement of more than 2 million stone blocks. The structure stands 481 feet tall, and is said to contain enough rock to build a 1 foot wall around the country of France.