Tens of thousands of people gathered along San Francisco’s waterfront on Sunday to mark the 75th anniversary of the Golden Gate Bridge, the distinctive orange structure that attracts 10 million visitors each year.

Some 2.7 kilometres long, it is 27 metres wide and its two towers reach 227 metres above sea level. Traffic is suspended 67 metres above the water

The city hosted a massive celebration complete with music, dance, vintage cars and motorcycles as well as a fireworks display showcasing the iconic structure at the entrance to the San Francisco Bay.

The celebrations took place 75 years to the day after the bridge was opened to the public: for pedestrians on May 27, 1937, and to traffic the next day.

At the time, the Golden Gate was the world’s longest suspension bridge.

Dreamt up by engineer Joseph Strauss, the bridge distinguishes itself by its unique colour, chosen by architect Irving Morrow and dubbed International Orange.

The paint originally ensured visibility for passing ships and served as a sealant to protect the bridge from the salty mist from the Golden Gate Strait after which it was named, the entrance to the bay from the Pacific Ocean.

Construction of the bridge took four years. Some 2.7 kilometres long, it is 27 metres wide and its two towers reach 227 metres above sea level. Traffic is suspended 67 metres above the water.

Pedestrians and cyclists can access the bridge along with motorists.

But the span also has a grim history as a popular place to commit suicide.

An estimated 1,600 people have died there in instances where the body was recovered, with many more unconfirmed, according to the Los Angeles Times.

Last year alone, 37 people died after jumping off the bridge –the fourth highest number since it opened, the newspaper said, citing data from bridge authorities.

Events marking the bridge’s anniversary are also taking place all year long, and a new visitor centre was opened in early May at the southern entrance.