Arriving in 1881, the French canal workers found thick jungle and swamps infested with malaria and yellow fever. Labourers also had to contend with poisonous snakes and insects and battle through acres of saw grass that could cut skin like a razor blade.

Thousands of tonnes of heavy construction equipment was imported, but much of the technology was ill-suited to work in the hostile Panamanian terrain. Frequent landslides would often erase weeks or even months of work.

When the Americans took over the project in 1904, the French plan for a sea-level canal was abandoned, but much work still had to be done to bridge the continental divide.

In an effort to improve living conditions and reduce the threat of disease entire new towns were built for the thousands of workers and engineers brought in to work on the canal.

The 12.6km (8.5 mile) long Culebra (later named Gaillard) Cut was the focus of the heaviest work. Dozens of steam shovels cut a path through the rock and shale and in the tropical Panamanian heat the temperature at the bottom of the cut would often exceed 50C.

In 1906 President Roosevelt (white suit, at left) came to see the excavations. It was the first time an incumbent president had left the US. "This is one of the great works of the world," he told the workers, "it is a greater work than you yourselves at the moment realize."

The canal's three sets of locks were the largest and most technologically advanced devices of their kind. Huge 12-metre-long steel moulds mounted on rollers were used to set the concrete.

In October 1913 the sluice gates were opened on the giant Miraflores Locks, flooding them for the first time. After more than 80 years of service the structure of the Panama Canal locks remains in near perfect condition.

The Gaillard Cut today: The Panama Canal remains one of the engineering wonders of the world.