From the sidewalk, you’d never know this buzzy new Southie spot hides an urban oasis. Housed inside a luxury condo building, Publico encloses an open-air atrium, adorned with leafy trellises, fire pits and semi-covered lounge seating with flat-screen TVs. It’s a charming setting for sampling chef Keenan Langlois’ globe-trotting plates and thirst-quenching cocktails like the Frida, a refreshing tequila-watermelon tincture poured at an outdoor bar overseen by co-owner Teodora Bakardzhieva, the first woman to sling drinks at late institution Locke-Ober.