Millions of Israelis crowded parks, nature sites, museums and army bases to celebrate the country’s 66th Independence Day Tuesday, forcing authorities to turn visitors away as some sites exceeded capacity.

Four heritage sites, the Atlit detainee camp, the Ayalon Institute in Rehovot, the Begin Center in Jerusalem, and the Bank of Israel Museum, also in Jerusalem, were closed to the public before noon Tuesday after being flooded with visitors.

Later, police began urging visitors to stay away from the Tel Nof and Ramat David air force bases, reporting overcrowding there.

“The parking lot of the [Ramat David] base is full,” the police tweeted from its official account.

The Israel Defense Forces opens many of its bases to the public on Independence Day.

In addition Israelis were treated to a flyover by military aircraft from Beersheba to the country’s north.

Police also said Ashkelon National Park was closed from overcrowding.

The Jewish National Fund said early Tuesday that it expected over a million visitors to hit Israel’s national parks and other sites, and deployed rangers to the sites to prevent littering and fires.

Barbecuing for Independence Day is considered a mainstay of the holiday.

Many main highways, including Route 2 along the coast and Route 1, which runs from Tel Aviv to Jerusalem, were plagued with heavy traffic.

Crowding was also reported on Route 73, between Nahalal and the Ramat David base. Highway 65, a major northern road, was also reported jammed