Shake Shack opens in the South Bay on Sunday

Maybe you saw the new sign go up on Rosecrans Avenue and your inner foodie did a double-take.

Yup, Shake Shack’s first South Bay location is opening soon in El Segundo. Like, Sunday.

The East coast burger chain, known for its Angus beef ShakeBurgers on potato rolls, crinkle-cut fries and frozen-custard “concretes,” will open the doors of its sixth Southern California location at 11 a.m. at Apollo Landing, a new row of fast-casual eateries at 2171-2191 Rosecrans Ave.

The first 50 customers in line will get a free Caramel Apple Fritter concrete made with a Randy’s Donuts apple fritter, vanilla custard and salted caramel sauce.

It’s one of three new flavors that will be served in El Segundo, according to a news release.

Five percent of sales from one of the other new concrete flavors, Pie Oh My, will benefit the Exceptional Kids Organization, a nonprofit supporting students with developmental and physical disabilities.

El Segundo’s Shake Shack also will serve a range of craft beer and wine and the Roadside Double cheeseburger, which is only available in California. Regulars can place their orders ahead of time on a smartphone app.

The New York-based chain opened a location inside Terminal 3 at Los Angeles International Airport in June after successes in West Hollywood, Hollywood, Glendale and Century City.

At 4,000 square feet, Shake Shack will be the largest restaurant in the 13,500-square-foot Apollo Landing dining complex, which replaces a longtime Cozymel’s Mexican Grill at the corner of Rosecrans and Apollo Street.

The space features green architecture and sustainable materials, including tabletops made of reclaimed bowling alley lanes, the company said.

The next Apollo Landing eatery set to open is Tender Greens, said Bryce Caster of Continental Development, ideally before Thanksgiving.

A Philz Coffee, Pier 76 Fish Grill and Caló Kitchen + Tequila are under construction and slated to open in March, Caster said.

A sixth restaurant on the east side between Pier 76 Fish Grill and Philz Coffee is to be announced.