The Great Wall of China is a series of fortifications made of stone, brick, tamped earth, wood, and other materials, generally built along an east-to-west line across the historical northern borders of China in part to protect the Chinese Empire or its prototypical states against intrusions by various nomadic groups or military incursions by various warlike peoples or forces. Several walls were being built as early as the 7th century BC; these, later joined together and made bigger, stronger, and unified are now collectively referred to as the Great Wall. Especially famous is the wall built between 220–206 BC by the first Emperor of China, Qin Shi Huang. Little of that wall remains. Since then, the Great Wall has on and off been rebuilt, maintained, enhanced; the majority of the existing wall was reconstructed during the Ming Dynasty. One of the most Famous Cultural Monuments and Wonders of the world.

5. Angkor Thom (Big Angkor)

Angkor Thom is a 3km2 walled and moated royal city and was the last capital of the Angkorian empire. After Jayavarman VII recaptured the Angkorian capital from the Cham invaders in 1181, he began a massive building campaign across the empire, constructing Angkor Thom as his new capital city. He began with existing structures such as Baphuon and Phimeanakas and built a grand enclosed city around them, adding the outer wall/moat and some of Angkor’s greatest temples including his state-temple, Bayon, set at the center of the city. There are five entrances (gates) to the city, one for each cardinal point, and the victory gate leading to the Royal Palace area. Each gate is crowned with 4 giant faces. The South Gate is often the first stop on a tour.

The Acropolis hill, so called the “Sacred Rock” of Athens, is the most important site of the city and constitutes one of the most recognizable monuments of the world. It is the most significant reference point of ancient Greek culture, as well as the symbol of the city of Athens itself as it represent the apogee of artistic development in the 5th century BC. During Perikles’ Golden Age, ancient Greek civilization was represented in an ideal way on the hill and some of the architectural masterpieces of the period were erected on its ground.

The National Chiang Kai-shek Memorial Hall is a famous monument, landmark and tourist attraction erected in memory of Generalissimo Chiang Kai-shek, former President of the Republic of China. It is located in Taipei, Republic of China (ROC).
The monument, surrounded by a park, stands at the east end of Memorial Hall Square. The structure is framed on the north and south by the National Theater and National Concert Hall.

The Sultan Ahmed Mosque is an historical mosque in Istanbul, the largest city in Turkey and the capital of the Ottoman Empire (from 1453 to 1923). The mosque is popularly known as the Blue Mosque for the blue tiles adorning the walls of its interior.
It was built from 1609 to 1616, during the rule of Ahmed I. Like many other mosques, it also comprises a tomb of the founder, a madrasah and a hospice. While still used as a mosque, the Sultan Ahmed Mosque has also become a popular tourist attraction.