The Louvre museum has reopened in Paris after its closure nearly four months ago due to the coronavirus pandemic.
Masks are compulsory, a one-way system is in place and numbers of visitors will be controlled.
There will also be a spaced queue to view Leonardo Da Vinci's famous Mona Lisa painting.
Some 10 million people come to what is thought to be the world's most visited museum each year, the majority from abroad.
With tourism crippled by the ongoing pandemic and the EU only opening its external borders for 15 nations so far, staff at the museum fear visitor numbers could drop hugely.
"We are losing 80% of our public," director Jean-Luc Martinez told AFP news agency.
"We are going to be at best 20-30% down on last summer - between 4,000 and 10,000 visitors a day.
" The museum closed on 13 March and has reportedly lost €40m ($45m; £36m) in revenue since then.
"We are lucky to be a state-owned museum," Mr Martinez told the New York Times in June.
Parisian tour guides protested outside the Louvre on Monday morning, saying the government had not done enough to help people who work in the tourism industry.
French President Emmanuel Macron declared a "first victory" over the coronavirus in June as he continued a partial lifting of lockdown restrictions.
But the government has faced criticisms throughout the pandemic over shortages of medical equipment and how it has handled the crisis.
On Friday it was announced that the Law Court of the Republic, which deals with claims of ministerial misconduct, will open an inquiry into the government's response.
The country has confirmed more than 195,000 cases of the virus and 29,813 deaths, according to Johns Hopkins University.