The Eiffel Tower in Paris is to have a 2.5m-high (8ft) wall of reinforced glass built around it as protection against terror attacks, officials say.
The Paris mayor's office says the wall will replace metal fences put up for the Euro 2016 football tournament.
The project, if approved, is expected to cost about €20m (£17m; $21m) and work should start later this year.
The French capital has been on high alert since attacks by jihadists in November 2015 left 130 people dead.
Last July, 86 people were killed when a lorry ploughed through a crowd celebrating Bastille Day in the southern city of Nice.
The Eiffel Tower, one of France's most famous landmarks, attracts more than six million visitors each year and the wall is designed to stop individuals or vehicles storming the site, said the assistant mayor for tourism, Jean-Francois Martins.
"The terror threat remains high in Paris and the most vulnerable sites, led by the Eiffel Tower, must be the object of special security measures," he said.
"We will replace the metal grids to the north and south with glass panels which will allow Parisians and visitors a very pleasant view of the monument."
Mr Martins added: "We have three aims - to improve the look, make access easier and strengthen the protection of visitors and staff."
The project will also involve reorganising pathways around the tower.
Earlier this month, a man wielding two machetes attacked soldiers at Paris's Louvre Museum.
President Francois Hollande said there was little doubt it was a terrorist act.