10 Chicago Venues for Company Picnics and Summer Entertaining

III Forks Steakhouse opened last fall near Millennium Park. With cabanas, stone fireplaces, and a knotty pine and granite bar, its rooftop lounge overlooks the park and the city skyline and can host events for 100 guests. The lounge has its own menu of small plates, with selections such as tobiko deviled eggs, lamb meatballs, and duck served in waffle cones.

The Chicago Botanic Garden's new Pullman Barn is open June through October. Situated among grasses and flowers, the rustic structure can seat 50 or host cocktail receptions for 80, and rental fees include picnic tables and benches. Fire pits are available for an additional cost. Culinary Landscape's catering menu focuses on Southern-inspired picnic fare such as jalapeno-cheddar corn muffins with whipped honey butter, barbecued shrimp, s'mores, and bourbon cocktails mixed with peach iced tea.

Estate Ultra Bar opened on Leap Day along the Chicago River. Available for buyout, the 8,000-square-foot venue can host receptions for some 260 guests. Several smaller areas are also available for private events. Later this year, a rooftop lounge will open, as will a riverfront dining area and a semi-enclosed patio called the Gazebo. The outdoor spaces will all be available for private functions, and though final capacities are still being determined, venue reps say that the alfresco spaces combined will hold more than 100 guests. Chef Chris Turano oversees the menu, where specialty items include lobster mac and cheese with a Goldfish-cracker crust. Mixologist Dan de los Monteros, formerly of the Aviary, stirs up seasonal cocktails.

After months of anticipation, Greenhouse Loft opened in November as part of the Green Exchange, an office and retail complex billed as the country's largest sustainable business community. The 3,500-square-foot event space can host functions for 250, and has an 8,000-square-foot organic garden that can host alfresco receptions for 250. Co-owners Steve Ewert and Jamie Davis are photographers and offer two photography packages.

The Lounge at the Plaza, a new outdoor lounge at the north end of Millennium Park, is open seasonally and hosts receptions for 150 or seated dinners for 125. Tented with white linen fabric, the space is filled with cushioned wicker chairs, stools, and high-top tables. Summery items on the cocktail list include spiked lemonade drinks and mojitos, and the appetizer menu offers Baja fish tacos, house-made hummus, and pulled-pork sliders.

BLT American Brasserie opened in December on the first floor of the former Montgomery Ward headquarters in River North and is designed to channel 1920s Europe. A large private dining room can seat 120 or hold 200 for cocktail receptions, and the room can be divided into two smaller spaces. Along Chicago Avenue, a massive back patio can host alfresco functions for 500, and the venue can arrange for tent rentals. In front, a patio that opens this spring has a 140-person capacity and can host private brunches, dinners, and cocktail receptions. Chef Laurent Tourondel, executive chef at Brasserie Ruhlmann in Rockefeller Center, oversees the menu. Items include coconut-macadamia-shrimp sushi rolls, oysters and little-neck clams from the raw bar, pizzas prepared in a brick oven, and steak frites.

Chicago Oak Brook Hills Marriott Resort has several outdoor areas for summertime gatherings, the newest of which is the Marquis Patio. Open since 2011, the space can host sit-down dinners or cocktail receptions for 100. Another alfresco space, the Gazebo Patio, can hold receptions for 300. The space looks out on the Chef's Garden, planted with vegetables and herbs that are used in seasonal menu items for the on-site restaurants. During the summertime, guests can watch chefs pluck the ingredients from the garden. In the golf club, the golf tent is open from April through October and can hold functions for 150. Hosts can arrange for barbecues, clam bakes, beach parties surrounding a heated outdoor pool, and teambuilding activities in each of the spaces.

Originally open in July 2011, Frontier's 125-seat patio added a full-service bar in October and four flat-screen TVs for presentations. By May, the space will have a retractable roof and an outdoor cocktail list with punch bowls and seasonal drinks. Group dinners can include whole-roasted pig, lamb, or goat with sides such as macaroni and cheese and johnnycakes.

In Glen Ellyn, Waterleaf Restaurant & Inn has a 40-seat patio that will debut this spring. The patio has fire pits, heaters, shade umbrellas, and water features inspired by a Zen garden. Executive chef Jean-Louis Clerc, who focuses on French and Italian fare, will reveal his spring and summer menus later this year. Reserving the outdoor space generally requires an interior booking as contingency, and indoor options include semiprivate event spaces in the restaurant and a second-floor conference room. The room can seat 80 in U-shaped or classroom-style settings and has a retractable screen, an LCD projector, and microphones.

Specializing in what its menu refers to as "cheese, swine, and wine," The Purple Pig is a collaboration between well-known restaurateurs Scott Harris, Tony Mantuano, and Jimmy Bannos. Menu items include Mediterranean-inspired small plates such as marinated olives, pork-fried almonds with rosemary and garlic, cured meats, and whipped feta with cucumbers. The casual eatery's heated, tented patio seats 40, serves the full menu, and can be rented for private events.