A Tia Bia is a family-run mountain restaurant and guesthouse at Barranco do Velho 2, N124 701Z, 8100-159, deep in Loulé municipality on the winding Serra do Caldeirão road. Book: atiabia.com.
The house has fed hikers, motorcyclists, and weekend drivers since the 1980s with hearty Portuguese mountain cooking: migas de caça, wild boar stew, oven-roasted black pork cheeks, kid goat, lamb shoulder, and garlic fried squid. Two heated interior rooms and two outdoor terraces fill fast. Parking is free on site, which matters after the hill drive.
The restaurant is closed all day Monday (and typically closed Sunday evenings) – plan around that before you drive up from Vilamoura or Quinta. Portions are large. Vegetarians will find starters but few main courses. Call or email to reserve, especially Sunday lunch.
Who it suits: couples and families with a hire car who want a real Portuguese mountain lunch; Via Algarviana walkers; repeat visitors who treat the drive as part of the day. Skip it without a car, for light eaters, or if you need Monday dining. Nine guest rooms sit on the same property if you want to stay overnight. Dogs are welcome on the terrace.
Inland alternative: Casa dos Presuntos in Cortelha. More: best restaurants in Loulé.