SEBRING, Florida – He hadn’t noticed the two sneakers tied together by their laces and hanging from a power line over the pits until someone pointed them out. Immediately, Marcus Ericsson understood the meaning.

The short course at Sebring International Raceway is the smaller, grittier portion of the full course on which the 12 Hours of Sebring has been held since 1952. The 12 Hours is one of world’s best and most significant auto races. It’s also largely unseen by the public, unless you’re into sports car racing or have been known to throw a pair of shoes over a power line, perhaps while setting fire to a couch.

IndyCar Series teams use Sebring’s short course often during the offseason, a suitable place to find warm weather and a circuit that mimics its venues – primarily street courses – to gather data for the upcoming season. Last year, the track was essential for teams trying to sort out the new aero kit. Last week, it was essential for a driver moving from Formula One to INDYCAR.

It gets a bit earthy at Sebring, and Ericsson appreciated that on first sight. In his first test in an Indy car and first visit to Sebring, he wrapped his arms around a car that’s tougher to drive than what he’s used to and a track like he hasn’t seen since he was a kid.

If you’ve never been to Sebring, your race fan card is in danger of revocation. Once an airfield used to train B-17 pilots during World War II, it’s the site of one of the longest continuously running auto races in America. Some of the best ever – Juan Manuel Fangio, Mario Andretti, Dan Gurney, Stirling Moss, A.J. Foyt and Phil Hill among them – have won here.

Sebring is a diamond in the rough. A very thick rough.

“I told Marcus when he showed up here, ‘Welcome to America. You’re racing on a World War II-era airport,’” said Taylor Kiel, Ericsson’s new boss at Schmidt Peterson Motorsports. “This is a historic place. They host international events, but it’s got its old-world charm, too. It’s bumpy. It’s dirty. It’s not a Formula One racetrack, right? But we come here for a specific reason, and it’s a good representation of street courses, which comprise a fair bit of our schedule. It’s a good place to test, for sure.”

The short portion of Sebring International Raceway on which the IndyCar Series holds its winter tests is an 11-turn section of the full, 17-turn course. Every March, the short course area is where most of the debauchery occurs during the endurance race weekend. It’s part spring break, part bar brawl and part auto race. Couches burn, clothing is removed, shoes get tossed over power lines, and – for those paying attention – some marvelous racing occurs.

Notoriously rough and challenging even for the best professional racers, Sebring is made even more difficult by a fine layer of sandy soil that’s perfect for central Florida orange groves but terrible for grip when it reaches pavement. Sebring doesn’t just hold a famous race; it creates famous racers. If you can’t handle this place, perhaps you should consider a career change.

That difficulty spoke to Ericsson in the first step of his transition from F1 to INDYCAR. At 28, the native of Kumla, Sweden, is rediscovering what first drew him to motorsports. Imperfection. Difficulty. Character. Sebring is old school. And old school is a good thing.

“It reminds me of back in the day when I was doing British F3 and stuff like that,” he said. “We were testing a lot on tracks like this – old airfields in the UK and tracks that were bumpy. … This track is fun to drive. It has a lot of character. All the curbs are different. It’s bumpy, and the bumps affect the car differently in each corner. In F1, every track is extremely smooth. All the curbs are the same everywhere. They try to make all the tracks the same, literally. This place is unique. Every piece of it is unique.”

Nine days before he arrived at Sebring, Ericsson raced at Abu Dhabi’s Yas Marina Circuit, a $1.32-billion, nine-year-old course that will take your breath away. Sebring has the ability to take your breath away, too, but in an entirely different way.

Welcome to Sebring, Marcus. If you like this place, you’ll love the streets of St. Petersburg.