The town is the major centre of Anglona historical region of northern Sardinia which lays in the middle of the Western coast the Gulf of Asinara. Initially the town was called Castelgenovese, then Castellaragonese and only then by its current name -- Castelsardo.
Castelsardo is a member of I Borghi più belli d'Italia, an association of small Italian towns.
- 1 Ufficio di accoglienza turistica (tourist reception center), Via Bastion, 1 (Palazzo Eleonora d’Arborea), ☏ , ✉ email@example.com. M-F 09:00-14:00, 16:00-18:00.
A local bus, Castelsardo - Lu Bagnu, connects the porto turistico (marina) with the town's centre.
- 1 Castello dei Doria (Doria Castle). The castle is the major landmark of the town. Originally the castle was built by Doria family from Genoa in the 12th century. Later on the town was emerged on the slopes surrounding the castle.
- Museo dell’Intreccio Mediterraneo. Jul Aug: 9:00-00:30; May Jun Sep: 09:30-21:30; Apr Oct: 09:00-19:00; Nov-Mar: 10:30-16:30. The castle hosts the Mediterranean Weaving Museum €3.
- 2 Concattedrale di Sant'Antonio abate (Castelsardo Cathedral). The cathedral is located at the northern edge of the medieval centre of Castelsardo, in a panoramic position overlooking the sea. The building blends the elements of the Catalan Gothic and the Renaissance. It was consecrated in 1622. The altarpiece contains a notable 15th-century painting Madonna con Bambino assisa in trono ("Enthroned Madonna and Child") attributed to the painter known as Master of Castelsardo.
- Museo Diocesano, via Manganella 42. May Sep: Th-Tu 10:00-13:00 15:30-19:30; Jun: 10:00-14:00 15:00-21:00; Jul Aug: 10:00-14:00 15:00-22:00. The Diocesan Museum is located at the crypt of the cathedral where among the artefacts you'd find some other parts of the original altarpiece by the Master of Castelsardo. €4.
- 3 Chiesa di Santa Maria delle Grazie. This medieval church has no facade, the entrance is on the right side of the building.
- 4 Palazzo la Loggia. The Town Hall since the year 1111.
- 1 Roccia dell'elefante (Elephant Rock) (Multeddu locality). It is a rust-colored heavily eroded roughly 4m in height block of granite which is said to resemble a sitting elephant. Its resemblance with an elephant was first noted by the scholar Edoardo Benetti in 1914. Before that it was known as Sa Pedra Pertunta (perforated stone). This stone used to be a part of the rocky complex upstream Castellazzu from which it fallen downstream. The rock is not only popular among the modern tourists, apparently it was a place of cult since the prehistoric time: there are two domus de janas from pre-nuraghic time located there.