Visit Cagliari
We had too much sun one day and decided to try and stay away from it for a while. So we took our rental car and drove down the coast to Cagliari, the capital city of Sardinia which is located on the Southern tip of the island. It has a harbour where cruise ships stop and a medieval walled quarter situated high above the rest of the town. This is a nice place to visit and offers great views. Architectural highlights include the 13th-century Cagliari Cathedral, the Bastione di Saint Remy from where you have beautiful views over the city, harbour, and some historic sights. When you visit during the day, the city feels quite empty as most shops are closed until 4 PM due to the heat. We found a lovely spot for lunch in a restaurant called "Taccas" with tasty local food and a nice outside seating area. Nice, but hot day trip. Maybe try this during the late afternoon or evenings...
Try as many beaches as you can
The area of San Teodoro is full of stunning beaches. Some are busier than others, but all of the ones we saw had beautiful clear water and white sands. The one closest to our hotel in Northern Sardinia is called Porto Taverna. Beautiful turquoise water, a little stylish beach bar where you can rent sunbeds and umbrellas. From this beach, you have beautiful views of the island Tavolara which is located in the middle of the bay. We also spend time at the beaches La Cinta and Lu Impostu which were both really pretty too. All beaches we visited had parking, a place to buy some snacks and to rent sunbeds and umbrellas too. There is no wrong choice with regards to the beach in this area in my opinion.
Find the Pink Flamingos
The Sardinians are proud of the lagoon of San Teodoro because it is one of the greatest natural treasures of the island. And the home of many many pink flamingos amongst all the birds that live here. There is a marked trail around the lagoon that can be followed or you book a trip on a boat around the lagoon to see the beautiful birds. Stunning landscapes, expert guides, and some great birds can be seen during this excursion. Only the flamingos were missing when we went. We saw one flamingo in the distance because June is not a time to see them at the lagoon. The start flying back here as of July, August time... still a fabulous and peaceful place to visit...