Machu Picchu
Machu Picchu is a result of the Inca Empire. It's made of cut stone fitted so closely together without mortar that a knife blade can't penetrate its cracks. It is situated on a high ridge and is bordered by a river on three sides. It is located in Peru. The walls of Machu Picchu were built with details that protect it from collapsing during earthquakes, such as the doors and windows being trapezoidal and tilt inward from bottom to top. Many people travel on foot to Machu Picchu every year to marvel at the beauty and architectural ingenuity.
Petra
Petra is a historical city in Jordan and is famous for being carved into the mountains surrounding it. It's thought to have been established as early as 312 BC. It was the home of the Nabatean kingdom, which was known for its advanced irrigation systems. The city is located in one of the rocks at an altitude of 900 meters above sea level.
The Roman Colosseum
The Roman Colosseum was built about 2000 years ago and was used for Roman sports at the time, namely gladiator games in which men fought each other and animals to the death. The Colosseum had 45,000 sitting places and 5,000 standing places. Under the arena was a large network of tunnels that were used for the gladiators, animals, and slaves. Every year the building is visited by millions of tourists.
The Great Wall of China
The Great Wall of China is a stone wall built from Shanhaiguan in the east to Lop Nur in the west of China, and it stretches over a distance of 8,851.8 kilometers. This structure includes man-made walls as well as natural trenches, and the natural defensive barriers such as hills and rivers. It was built between 5th century BCE and 16th century BCE in order to protect the northern borders of the Chinese Empire from the nomadic tribes.
Taj Mahal
Taj Mahal, famously known as the Symbol of Love, is a mausoleum built by the Mughal emperor Shah Jahan for his wife Mumtaz Mahal. It is located in Agra, India. Taj Mahal's construction began around 1632, and it took around 21 years to be completed. It was constructed according to the Mughal architecture, which is a combination of Persian, Indian, and Islamic styles.
Chichen Itza
Chichen Itza is a Mayan pyramid that has been around since between 550 AD and 800 AD. It was mainly used for Mayan ceremonies before being abandoned until 900 AD. Its name means “at the mouth of the Itza well.” It's located on the Yucatan Peninsula in Mexico. Climbing to the top of the pyramid is currently forbidden.
Christ the Redeemer
Christ the Redeemer is the statue of Jesus Christ in Rio de Janeiro, Brazil. It is situated at a height of 700 meters on the Carcovado mountain, in the Tijuca forest National Park. It is built of reinforced concrete and soapstone, and is the symbol of Christianity, as well as of Rio de Janeiro.
Note that from the old wonders of the world the last remaining monument of the ancient wonders is Giza Pyramid Complex, also known as Giza Necropolis. It consists of three pyramids that are known as the Great pyramids and one huge sculpture called the Sphynx.