The show is rain or shine and runs through May 31.
"We have a little bit of something for everyone," said Country Fair Chair Christine Conners.
This is the oldest and largest outdoor multi-breed horse show in North America.
"It is one of the top prestigious horse shows in the country. Kids try to qualify for this all year long, so if you make it here, you're showing and competing with the best riders," said show manager Pat Boyle.
The horse show draws more than 1,500 competitors and 125,000 attendees each year.
This is an elite competition.
"It is something that people strive and work for all year to qualify for," said show manager Phil DeVita.
"So many riders started here, developed here, became Olympic riders. We have many Olympic riders here competing with us," added DeVita.
While people come from all over the country, and the world, to compete, this is also an opportunity to showcase local talent like 14-year-old Kinsley Nolte from Downingtown with trainer Troy Hendricks.
"It is really such a special show with so much history here. It is so cool to be among the top level of people, who have competed here for so many years, and it is so special because it is so close to home-we live about 30 minutes from here," Nolte told ActionNews, about an hour before she competed herself.
"You see the sign that says, 'Where champions meet', and I mean, there's nothing more iconic than that sign," Hendricks said.
"This is an event we work towards for several months- we plan our show schedule around it, we plan our practices at home around it," Hendricks added.
There are rides and carnival games in addition to treats, like the signature lemon sticks.
"It is kind of like nature's lemonade! We take a lemon, we take off the top third of it and put in a delicious candy stick, and it turns into a little straw," explained Conners.
Vendors, like Sunskaara, set up pop-up shops.
"All the designs you see showcases the Pennsylvania lifestyle," said Garima Malhotra, owner and designer of Sunskaara, who showed us a blue and white pattern inspired by her own backyard in Wayne.
Sunskaara's Vice President of Sales Sophia Garceau said, "It has been such an amazing tradition and to actually really part of this is a huge honor."
There will be a Memorial Day tribute on Monday evening.
The Grand Prix, featuring Olympians and top competitors from around the world, takes place on Thursday.