Liguria in 3 days = Cinque Terre (2 villages + 1 hike) + Portofino (the piazzetta + trail to San Fruttuoso) + Genoa (old port, the caruggi, the pesto). The coast that invented the word Riviera, where every village is vertical and every meal starts with focaccia.
Each day is a logical geographic loop. Mornings for sights, afternoons for food, evenings for aperitivo. Car essential in Liguria.
Day 1: Cinque Terre. Train from La Spezia. Vernazza (harbor + Castello Doria) + Manarola (sunset from cemetery terrace). Hike Vernazza-Monterosso if time (2h, the best section). Day 2: Portofino peninsula. Santa Margherita Ligure (base). Bus/walk to Portofino. Trail to San Fruttuoso (2h) or Paraggi beach. Day 3: Genoa. Train from Santa Margherita (40 min). Old port (Renzo Piano Aquarium area). Caruggi (medieval alleys — the largest medieval old town in Europe). Pesto al mortaio at a trattoria. Via Garibaldi palazzi (UNESCO Strade Nuove).
Best time: April-June, September-October. Agriturismi 60-100/night with breakfast. Book 2-4 weeks ahead in summer.