The seven wonders of the ancient world:

Seven a sacred number:

In Egypt and Babylon the people thought that 7 was a special number because it's the sum of three and four. Three represented the basis of a family: mother, father and children, and four because of the four directions of the compass.

The Greek and later the Christians associated three with the Gods-father, Jesus and the Holy Ghost and four with the 4 elements (fire, water, air and earth).

But not only in religions seven is a mysterious number even in tales  as well. For example: "Snow-white and the seven dwarves" or "seven with one blow".

Antipatros of Sidon was the first who ever described the seven wonders. His book was a kind of travel guide through the ancient world.

The pyramid of Khufu:

The pyramid is the oldest of the seven world wonders. It is also the only one that has survived. The pyramid is named after his builder pharaoh Khufu (2551- 2528 BC), his name in Greek was Cheops. It is except the Great Wall of China the largest structure built by man. It is 480 feet high and it covers 251 yards square.

Only for the preparations, they needed 10 years. Many people worked on it. But they needed 20 years to complete the building. In 1168 AD the Arabs invade Egypt and they took the lip of the pyramid away.

The Hanging Gardens of Semiramis:

They were built in Babylon. Probably it was a gift from Nebuchadrezzar to his wife- a Persian princess- whose name maybe was Semiramis. Maybe the king had it built for his wife to compensate his frequent absences. The writers of that time in which the gardens were designed agreed that the gardens were very beautiful and full of life. It was not only a garden there were 7  different terraces. The trees, bushes, and flowers looked if there were hanging.

The statue of Zeus at Olympia:

Phileas worked on the statue. The temple in which the statue was situated, was built from 470 BC to 457 BC. The not clothed parts of the body were covered with irony. Zeus´ hair, his clothing and his sandals were made of gold. The eyes were precious stones. The figure was 400 feet high. It is one of the wonders because the statue was the largest and best-known image of the Greek gods.

The Temple of Artemis:

The Temple was built towards the end of the 2^nd millennium BC in Ephesus. A Greek historian, Ampelius wrote that it was the greatest, most beautiful and most noble sanctuary in all the world. It survived 1000 years but in 356 BC, a fame-seeking Greek named Herostratos set fire to the temple of Artemis. Under the ruins, they found a completely unharmed Stature of Artemis. Three years later, they tried to build it again, but in 380 AD the Christians religion became the state religion and the Roman emperor ordered that all pagan temples got closed.

The Tomb of Mausolus:

The Tomb was situated in Harlicarnassus. Mausoulus wanted to be immortal and because of this, he invited all Greek artists to take part in a competition to design the most beautiful tomb. The architects Satyrus and Pythius won the competition. Mausoulus did not survived till it was built, so his wife and sister, Artemisia, completed it. But she did not survived either. The architects finished the tomb themselves. They built 25 years to complete this monument. The tomb was destroyed in the 12 century AC because of an earthquake.

The Colossus of Rhodes:

On the sunny island of Rhodes Helios have a special position among all the Greek gods. Therefore, the people of this island rushed to fulfil their promise to him. So they gave Chares of Lindos the commission to build the statue. He started 302 BC. Finally, the statue was 104 foot high. (The statue of liberty is only 35 feet smaller than this statue). In any case, it only remained standing 66 years. They did not rebuild it because an oracle said that Rhodes would suffer a lot if they did it.

The Pharos of Alexandria:

In 300 BC, the people of Alexandria, a town in Egypt, started to erect the Pharos. It was situated in Alexandria and it was 430 foot-high. Its not clear who built the monument, but it survived for almost 1000 years all the fortunes and wars unharmed. In 796 AC, it collapsed during an earthquake.