At the Kentucky Derby, all eyes are on the horses. As they race around the historic track at Churchill Downs, the world watches, gripped by what’s known as “the most exciting two minutes in sports.” But for photographer Lili Kobielski, the real action is somewhere else: up in the stands.

Held annually on the first Saturday in May, the Kentucky Derby may be the world’s most famous horse race, but it’s arguably just as famous for its fashion. “There’s really nothing like it,” says Kobielski, who grew up around racing and has photographed the Derby for more than a decade for Vogue. “I especially love the diversity of the racegoers and the general ebullience of the crowd. The energy is electric and the huge hats, colorful outfits, and incredible characters make it an endlessly engaging subject.”

Now, Kobielski has collected the best of her 15,000-odd photographs from the event into a new book, At the Derby: Kentucky’s Grandest Celebration of Fashion.

For her first Vogue Derby story in 2014, Kobielski focused her lens on Rosie Napravnik, the only female jockey riding that year—and of course, all the fun Derby fashion. “I love the range of looks from subtle and chic to completely outlandish,” she says. “It’s impossible to get bored photographing here.”

Below, in honor of the 152nd running of the Kentucky Derby today, see some of our favorite shots that Kobielski has taken at the track over the years.