The Eiffel Tower, one of the most visited tourist sites in the world, closed on Monday as staff went on strike in protest against the way the Paris monument is managed financially, disappointing the crowds below.

The strike comes as Paris prepares to host the 2024 Summer Olympics, which begin on July 26 and will feature metal from the tower in the winners' medals.

Visitors stood outside the barriers of the tower grounds in front of a giant screen announcing the strike.

"It’s a real shame, really, because we come just for three days, and we’re not going to be able to get up,” Nelson Navarro, from Norfolk, England, said.

Vito Santos, from Canada, had planned to revisit the monument 15 years after his honeymoon and show if off to his children.

"It's disappointing... The plan was to come here really early to get a ticket as early as possible. However, it was a surprise for us, the strike is here, so we cannot make the tour,” he said.

Unions claim Paris City Hall, which owns 99% of the company that oversees the tower, Societe d'Exploitation de la Tour Eiffel (SETE), is underestimating the cost of maintenance and repairs to the monument planned ahead of the Olympics.

This in turn could result in lax maintenance work and put visitors at risk, they say.

This is the second time this year staff have gone on strike for the same reason.

The wrought-iron 324-meter (1,063 ft) high tower, built by Gustave Eiffel in the late 19th century, welcomes about six million visitors each year.