There’s no sight quite like it anywhere on the planet - some 50 miles born of great sacrifice and incredible ingenuity.

More than 100 years ago, workers carved the earth to make a trench as big as the expanse between Tampa and Bradenton. A man-made lake serves as the blood supply to the Panama Canal.

Tens of thousands of tourists visit the Panama Canal every year to see first-hand how huge vessels pass through a narrow waterway connecting the Pacific Ocean to the Caribbean Sea.

“You wonder, how could this work?" said Fernando Vasquez, who was visiting from Barcelona, Spain. "Seeing it [in person] is something else."

The Panama Canal Authority says more than 1 million ships have transited the waterway in the past 100 years. About 40 ships go through per day.

Without the Panama Canal, ships would have to sail approximately 8,000 miles around the southernmost tip of South America. That would take weeks.

The PCA says thanks to the Panama Canal, the journey through Panama today takes on average of 8 to 10 hours. Some transits can be 12 hours long.

The Panama Canal is like a two-lane road where ships come and go in opposite directions. The waterway features a system of three locks that operate as water elevators, raising ships to the level of Gatun Lake and then lowering them back to sea level.

One hundred years later, this engineering marvel is still key to shipping.

The history of the Panama Canal construction dates back to 1880, when the French tried and failed to build a shortcut for ships through Panama. The U.S. began construction in 1904 under the leadership of President Theodore Roosevelt. As a result of the Hay-Bunau-Varilla Treaty, the U.S. paid Panama at the time $10 million to acquire the Panama Canal Zone.

The Panama Canal was finished in 10 years, but not without enormous loss. Disease and dangerous work conditions killed thousands of workers.

The cost of building the Panama Canal was an estimated $375 million at the time. In 1914, the S.S. Ancon made history as the first ship to complete the journey through the Panama Canal.

Rising tensions and a crisis in 1964 eventually lead to the Panama Canal treaties. Twenty-one Panamanians and 3 U.S. soldiers were killed in riots at the Panama Canal Zone in January of that year.

Under the leadership of the Carter administration, the Torrijos-Carter treaties were signed in 1977 to return the canal to Panama. The transition began and in 1999, Panama took full control of the canal.

Panama Canal Expansion

Today, a more than $5-billion expansion is underway to widen and deepen the Panama Canal.

“The goal of the expansion is bringing in more cargo and more equipment,” says Panama Canal Authority Civil Engineer Luis Ferreira.

The expansion has been plagued by delays and cost overruns. Ferreira says the expansion should open in December 2015.

Currently, each ship that transits the Panama Canal can transport up to 4,500 containers with goods that include electronics, furniture and clothing. The bigger ships that will cross over on the expanded canal will carry 3 times that.