Sardinia's appeal splits fairly evenly between its coastline and its interior — ancient ruins, dramatic caves, and beaches that hold up against anywhere else in the Mediterranean.
1. Neptune's Grotto (Grotte di Nettuno)
A vast sea cave near Alghero, reached either by descending the 654-step Escala del Cabirol staircase (roughly 15-20 minutes down, longer coming back up) or by a scenic 35-40 minute boat ride from Alghero's port — note the boat and cave-entrance tickets are sold separately. Hours run longer and boats more frequently from spring through autumn, with a reduced winter schedule, so check current times if visiting outside peak season.
2. Su Nuraxi di Barumini
A UNESCO World Heritage nuraghic complex — a Bronze Age stone tower structure unique to Sardinia — open daily from 9am with closing times that shift seasonally. Entry is guided-tour-only, with tours departing roughly every half hour and lasting about an hour, so it's worth timing your arrival around a tour slot rather than showing up expecting immediate entry.
3. Costa Smeralda
The glamorous stretch of coastline around Porto Cervo in the northeast, known for turquoise coves and upscale marinas. It's free to explore by car, and even without the yacht-set budget, the coastal drive and beaches are worth the detour.
4. Cagliari's historic center
Sardinia's capital rewards a half-day of wandering — the Bastione di Saint Remy terrace, the hilltop Castello district, and Cagliari Cathedral are all free or low-cost, and the city stays fully operational year-round unlike many of the seasonal coastal resorts.
5. Cala Goloritzé or Cala Luna
Two of Sardinia's most photographed coves, both reachable by boat from nearby towns or by hiking trails of varying difficulty. Cala Goloritzé sits inside a protected natural monument, so swimming access can have seasonal rules — check current conditions before planning a full day around it.
Worth knowing
A rental car opens up far more of Sardinia than public transport alone, especially for the interior ruins and quieter coves. If your trip lands anywhere near August 15 (Ferragosto), expect the coastal towns and beaches to be at their most crowded of the year.