TALLADEGA, Ala. — One of the biggest weekends in the NASCAR playoffs is underway at Talladega Superspeedway, where fans from across the country and around the world are gathering for high-speed racing, live entertainment and one of the most unique atmospheres in sports.

The 2.66-mile tri-oval is the longest in NASCAR. With 33-degree banking, Talladega is also the steepest, allowing drivers to reach speeds nearing 200 mph. The track seats 80,000 and is the only NASCAR venue that offers free camping — a major draw for fans planning to stay the entire weekend.

This year’s event features three days of activity, including tailgating, multiple playoff races and off-track events. Friday night there is a rodeo, and a concert featuring Whiskey Myers is scheduled for Saturday.

“Our iconic infield opened yesterday, and the line was miles long,” said Brian Crichton, president of Talladega Superspeedway. “We’re ready — three great playoff races this weekend — and the world is here.”

The infield has become one of the sport’s most well-known experiences. Fans from all 50 states and at least 26 countries are expected to attend.

“I kind of call this the world’s largest unofficial family reunion,” Crichton said. “We might not be related by blood, but we’re related by Talladega.”

Bo Fullen, a fan who has attended races at Talladega every year since 2011, said the atmosphere is unlike anything else in sports.

“You have to experience it — from the quiet in the morning to the rowdy at night,” Fullen said. “We’ve had Canadians, we’ve had people from Australia, we’ve even had a German with us one year. You just meet a little bit of everybody.”

For many, coming to Talladega is a tradition passed down through families or shared among friends.

“We’ve been coming here for 20 years,” said Allen Gros. “It’s the atmosphere — it’s the party. We’re from all over and we just meet at the racetrack..”

Fullen added, “It’s hard to envision this many people coming together, but it’s like one big happy family.”

While the social aspect draws crowds in, it’s the racing that keeps fans on the edge of their seats.

“To hear the rumble and roar of 40 cars going 195 to 200 miles per hour through this tri-oval is insane,” Crichton said.

Three playoff races will run throughout the weekend, bringing championship stakes to one of NASCAR’s most unpredictable tracks.

“There’s so much to do at Talladega Superspeedway,” Crichton said. “Everybody has got to come out.”