The longest man-made structure is the Great Wall of China. It is 13,171 miles (21,196 km) long and was built in 221 BC by the first emperor of China.

Nebuchadnezzar II (r.605-562 BC) built the hanging gardens of Babylon. His wife, Amytis, was sick and missed the plants of Media. To comfort her, he had these gardens built.

The Taj Mahal, built in the memory of Mumtaz Mahal, wife of Shah Jahan, is a blend of three styles of architecture: Indian, Persian, and Islamic. It is situated in Agra, India.

The Colosseum in Rome is said to have the capacity to seat 50,000 people at one time. It was a massive amphitheater and is among the seven wonders of the world.

The seven wonders of the modern world include wonders from the 20th century. The list includes the Empire State Building in New York, among others.

Giza in Egypt is known to have three massive pyramids. They are named Menkaure, Khafre, and Khufu. The pyramid complex is also known as the Giza Necropolis.

The ancient city of Petra is in Jordan and is famous for its pink color as it is made of red sandstone.

Chichen Itza in Mexico is said to be the largest Mayan city ever built. Travelers report unusual sounds are often heard from this place.

The Lost City of the Incas, also known as Machu Picchu, is one of the lost cities of Peru. It is said to have been built in 1450.

The final resting place of the 4th century BC satrap of the Persian empire known as Mausolos of Caria is The Mausoleum at Halicarnassus. It has a statue of a chariot pulled by four horses.