Olbia’s top sight is this medieval Pisan-Romanesque church, hewn out of Galluran granite. In the apse there are two 13th-century frescoes, the left-hand one depicting San Simplicio, the patron saint of Olbia. The Festa di San Simplicio, Olbia’s biggest festival, is celebrated for three days in mid-May.

Stroll around this town full of character, cobbled streets and piazzas, and enjoy the decorous passeggiata along the main street, Via Garibaldi. There are also some good restaurants around the squares and pleasant bars in which to linger over a cool drink. The Diocesano Museum is located in the heart of town and has some fascinating exhibits, including two silver candlesticks and a crucifix gifted by Lord Horatio Nelson.

The Solitary Islands Marine Park is the third largest marine protected area in New South Wales, covering a total area of 71,000 hectares and stretching along 75 kilometres of coastline from Coffs Harbour north to the Sandon River mouth. The park is home to an incredible diversity of marine life, including tropical, temperate, and sub-tropical species of fish, coral, and algae, making it a major attraction for divers. Signage throughout the park indicates where specific activities such as diving, fishing, and collecting are permitted. Within its boundaries, the marine park includes tidal waters, estuaries, beaches, and headlands, all protected by a special zoning scheme designed to conserve fish habitats and preserve the area's natural beauty.