The number seven is predominantly chosen by the greeks as they believed that it is a number of perfection and plenty. Additionally, it is the summing up of five planets(known at that time), moon, and sun. The ancient Greek historian and travel writer Herodotus is traditionally given the credit for choosing the seven ancient wonders of the world. His original list has been lost, but there are several references. Whether they were accurate or not, there’s no way to know.
The Colossus of Rhodes was considered to be one of the ancient Seven Wonders of the World owing to its unbelievable size. It was a statue of Helios, the Greek god of the Sun. Standing between 100 and 110 feet tall, it was the tallest statue of its time. Another feature that made the Colossus a ‘wonder’ was it gleamed and glistened when hit by the rays of the Sun seeing that it was composed entirely of bronze. Bronze is a metal alloy that is mainly made of copper mixed with a little amount of tin. More powerful than iron, it can endure severe weather conditions.
To build the Colossus of Rhodes, the workers molded the exterior bronze surface. The base was made of white marble. It is believed that the feet and ankle of the statue were first fixed. The structure was gradually upraised as the bronze form was supported by an iron and stone skeleton. They constructed a slope to reach the higher parts. It stood about 33 meters high.