On Monday, a ceremony on the outskirts of Panama City marked the beginning of a $5.2 billion Panama Canal expansion project, which aims to double the canal's capacity.
Despite blistering heat and occasional storms, thousands of Panamanians lined the banks of the canal to celebrate the start of the works.
The expansion plan was overwhelmingly backed by voters in October. It is due to be completed by 2014 - in time for the canal's centenary celebrations.
This Singapore container ship, too wide to cross the Panama canal at its current width, is having its cargo transferred to the other side of the canal at a private port.
The canal has historic links to the US, which used to own and run it. US President Theodore Roosevelt, pictured left in 1906, negotiated for the US to take control of the canal.
Steam shovels clear the last pile of rock in 1913, completing one of several deep cuts along the route of the Panama Canal. Construction cost $375 million and over 25,000 lives.
The US president who handed the canal back to Panama in 1977, Jimmy Carter, attended Monday's ceremony alongside South American dignitaries.
Today Panamanians are extremely proud of their canal. They held up photos of President Martin Torrijos (pictured far right), and of his father, former General Omar Torrijos (left).
Dynamite was used to blast away part of a hillside next to the canal. The project will involve the removal of 47 million cubic metres of earth and rock.