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One of the most important construction  projects in the history of mankind was the building of the Panama Canal.
The Panama Canal has influenced the development of trade across the globe.
The construction of the canal, shortened the distance between many ports on the Atlantic and Pacific oceans for about 8,000 miles (13,000 kilometers).
According to the first idea, the Panama Canal was supposed to be built by the French at the level of the sea, with depth of 30 feet (9 meters), and width at the bottom of 72 feet (22 meters).
However, the French plan was not realized and in 1904 The United States accepted the construction of the canal.
The French plan to dig a canal below the water level, from one ocean to the other, was dangerous.
In fact, if the differences between high and low tide on one side of the ocean were larger than the other, there would be major currents trough the channel.
This plan also required a lot more digging. Given these problems, it was decided to build a canal with locks, which meant that it must provide water at a higher altitude, in order to meet more parts of the channel.
This has been achieved with the erection of dams on the Chagres River.
Dams form one kind of staircase, through which the ships come into the channel. Ships are raised in some places where the water level is higher, and then descend to the other places.
Almost half of the canal passes through Lake Gatun.
Ships coming from the Atlantic are raised to the level of the lake by 92 feet (28 meters) through a series of three dams. On the other side - Pacific Ocean there is one notch 8 miles (13 kilometers) long. The ships then are being suspended 33 feet (10 meters) in the first dam and 60 feet (18 meters) through two other dams, so go down to sea level. Through the dams the ships are pulled with electric locomotives moving along the coast. Today, trough the dams even the largest ships can move.