Besides the beaches and boats and pools and parties, there’s plenty more to do in the Hamptons — even refreshingly affordable daytime activities for the day-trippers. Hamptons season begins on Memorial Day weekend, with many seasonal spots reopening for the year on the unofficial start of summer. At Gurney’s Montauk Resort & Seawater Spa, this weekend will be the grand opening of its Regent Cocktail Club, so expect an all-out party DJed by Mike Nouveau, Franco V, Dexter Love and Doug Grayson beginning at 3 p.m. Over at party headquarters 1 OAK Southampton, arguably the Hamptons’ most stylish nightlife venue, kick off a summer of A-list performances (past guests have included Busta Rhymes, 2 Chainz and Lil Jon) with Sunday’s show by Jus Ske and a special appearance by Fetty Wap, who’s already got one of the songs of the summer with “Trap Queen.” The Watermill Summer Benefit, at 6 p.m. on July 25, is the ultimate hot ticket. Art, music, theater, fashion, food and drinks blend for this incredible night of one-of-a-kind installations and performances throughout the eight-acre grounds (39 Watermill Towd Road). Sure, the cheapest ticket might be $500, but it all goes toward supporting young artists within the Watermill Center’s Artist Residency program.This year’s theme is “Circus of Stillness: The Power of Wild Beasts.” RELATED: What’s new in the Hamptons for summer 2015 Eat your way through three events comprisingDan’s Taste of Summer,showcasing the best of the East End. At Bridgehampton on June 17 is GrillHampton, a grill-off pitting eight NYC chefs against eight Hamptons chefs. The next day is Taste of Two Forks — no competition here, just the best food, wine and products from the North and South forks. Dan’s Harvest East End closes the foodie fest on Aug. 22 at McCall Vineyard and Ranch, focused on the wineries and restaurants of the North Fork and benefiting local agriculture. DansTasteOfSummer.com The Hamptons’ biggest LGBT party of the season, the Hamptons Tea Dance, takes place from 4 to 8 p.m. on July 18 at Nova’s Ark Project in Southampton (60 Millstone Rd.) Spend a festive afternoon in the park with dancing, refreshments and live music in a family-friendly atmosphere. (Read: you at the cocktail bar, kids in a special play area — it’s a win-win.) The park is known for its stunning outdoor sculptures, so don’t forget your camera. Proceeds benefit the Pride Agenda, a civil advocacy group for LGBT New Yorkers and their families. Throughout the season, the Mulford Farm Museum hosts various events to find new treasures to remember your summer by, including the East Hampton Antiques Show on July 18-19. Hunt for artifacts, textiles, jewelry, artwork, lawn ornaments and furniture from more than 50 local dealers. Early buying starts at9 a.m. for $20, but entry throughout the day is $10. If you’re feeling fancy, join the special opening-night party with cocktails and light bites on July 17, from 6 to 8:30, with tickets starting at $150 to benefit the museum and the town’s historic structures. Every year, the Clamshell Foundation hosts the East Hampton Sand Castle Contest on Atlantic Avenue Beach in Amagansett to benefit various charities. This year’s event is onAug. 1, starting at 9 a.m.; by 4 p.m., expect larger-than-life creations by teams of up to six people, from kids to pros vying at a level that always turns out breathtaking sand sculptures. You can register up until the morning of for a fee of $10, but strolling along to see the works in progress and the finished is completely free. Attending horse shows and polo matches is one of the top non-beach activities in the Hamptons, so make time for the 40th anniversary of the Hampton Classic, which takes place Aug. 23-30. As the first stop for the FEI East Coast World Cup, this is where it all kicks off for many jumping competitors and the stakes are high. Perfect for people-watching (especially of the famous variety) at the Grand Prix on Closing Day, this is event signifies the last weeks of summer for Hamptons regulars, so expect an excess of last hurrahs. Entering the Hampton Classic Showgrounds (240 Snake Hollow Road) is a very reasonable $10 per person or $20 per car; Grand Prix tickets (an additional $25-$35) go on sale June 1.