The US Open, the biggest pro tennis event in the United States (and one of the four Grand Slam tournaments that are the sport's most prestigious), returns to Flushing Meadows Corona Park August 27 through September 9. It's a chance to see the sport's heavyweights, like Caroline Wozniacki, Rafael Nadal, Victoria Azarenka and Novak Djokovic, up close as they battle for glory and prize money—the purse is more than $3 million for the singles winners. While any tennis fan is fairly certain to have a great time at the Open, we've put together nine tips to help you get the most out of your visit to the .For tickets, visit .1. There's a roof on Arthur Ashe Stadium.Those who've attended the US Open recently (or watched it on TV) have probably noticed the new retractable roof at Arthur Ashe Stadium. That means no more weather-related cancellations—if you buy a ticket for a match at the main stadium, you can be confident that it'll take place.2. Actually, most of the grounds have been renovated.Speaking of roofs, USTA officials describe the new Louis Armstrong Stadium—set to host its first matches this year—as "the world's first naturally ventilated tennis stadium with a retractable roof." For ordinary fans, this means a stadium with the advantages of a roof (no need to worry about rainouts, plus some protection from the afternoon sun) but the feel of the outdoors.In recent years, the USTA has renovated almost all of the side courts at the Billie Jean King National Tennis Center. The added seating has increased total capacity on those courts by more than a third. The USTA has also expanded walkways and added more concessions (and, yes, restrooms) throughout the grounds.There's also a new 8,000-seat grandstand stadium that opened in 2017.3. You can get in free or cheap.It's true. Though this is tennis at its highest level, you can still get an evening-session ticket for as low as $38. If you have a family, you may want to consider paying $10 for Arthur Ashe Kids' Day on August 25. You can also attend—for free—the qualifying tournament (August 21—24), in which ambitious players battle for a berth in the main tournament, and practice day, when the stars hone their game in preparation for their moment in the spotlight. There's no charge for grounds admission on Doubles Day (August 26). Also check out the Fan Fest and free practices in the days leading up to the tournament. For details on all the highlights of what the US Open calls "Fan Week," visit .4. It's not just tennis.Even if you're not a superfan (or if you're attending with someone who's not so into tennis), you can still be entertained by festivities at the Open.This year's Arthur Ashe Kids' Day includes music from artists like Echosmith and Brynn Elliot. There will also be interactive and entertaining tennis-related activities, plus appearances by athletes including Serena Williams, Madison Keys and Rafael Nadal.Opening night (August 27) always brings a lot of star power. This year, that includes a musical performance from Kelly Clarkson.Aside from the music and kid-friendly fun, there's plenty of —which most everyone enjoys. Options include Ben & Jerry's ice cream, the upscale Aces wine and sushi bar, a glatt kosher cart and even a Carnegie Deli outpost. Bargain seekers can hit the street vendors near the grounds, too, though security won't let you enter with outside snacks.5. Use public transit.It's going to be tough to get parking, and a spot will set you back $23. Best to just take the train, and that goes double on days when the Mets are playing at home.6. Wear a hat and sunglasses, and apply plenty of sunscreen.Seriously—if you are outside for a day session and don't take sun-protection measures, you are in line for some nasty burns.7. Know the rules.Like all other big events, the US Open has a lengthy list of what is and is not allowed. Do yourself a favor and to prevent that awkward moment when you can't bring your alpaca in to sit with you.8. Embrace the side courts.You don't need a courtside ticket to get a great view—you just need to know where to look. If you buy a , you'll be able to see the pros at very close range on the numerous side courts (and at a fraction of the cost of a courtside seat in one of the stadiums). 9. By the way...Fans aren't the only ones excited to explore New York City during the US Open; the players get pretty stoked as well. Take it from Roger Federer and Ana Ivanovic.