On Saturday, April 30, the general public will be able to share a secret that staff and management of The Logan hotel have experienced for the last couple of weeks:

Assembly Rooftop Lounge, built atop the Logan Circle hotel formerly known as the Four Seasons.

It's nine stories above the Parkway (and the hotel's Urban Farmer restaurant), and boasts a sweeping view from City Hall to the Art Museum and Fairmount Park. (Staffers haven't been drinking there; rather, they have simply been enjoying spring during the final touch-ups and run-throughs.)

Bower Lewis Thrower Architects and Dawson Design Associates set up the terrace with comfy modular seating, backed by an open-air lounge tucked behind retractable doors.

Lounge "pods" can be set to offer semi-private seating for up to 12 people. Two pods surround working fire pits.

Specialty at the walk-up bar is the selection of 10 champagnes and sparkling wines by the glass and by the bottle. Among the by-the-glass selections are Veuve Clicquot Yellow Label, Henriot Brut Souverain, and Grand Vintage Rosé Möet & Chandon 2004.

Batched champagne cocktails will be served on draft, including an Aperol Spritz with Aperol, lemon and rosemary, and a French 75 with Tanqueray, lemon sherbet and orange blossom water. Champagne pours, at different prices, will top off the cocktails.

The menu is to include oysters with soy mignonette, fresh wasabi and cilantro sprouts; nectarines and ricotta (house-made ricotta and stewed nectarines with grilled bread, grilled scallions and honey drizzle); baked Brie with vegetables, roasted fingerling potatoes, cherry jam and toast; yellowfin tuna tartare with pickled green papaya, ponzu, sesame and taro chips; a garden mezze including roasted garlic and white bean puree, tapenade, berbere-chickpea salad, raw and cooked vegetables, sunflower seeds, herbs and pita chips; and charcuterie.

Access is through a devoted entrance at street level on the hotel's Logan Circle frontage. Inside the door, two elevators will operate simultaneously, with one host at the bottom and another at the top working from synchronized iPads to manage the crowd

It will open at 5 p.m. Monday through Thursday, and at 3 p.m. Friday through Sunday.

April 30's opening starts at 7 p.m.