Complex sentence: Sassari is located in north-western Sardinia, at 225 metres above sea level, it rises up on a vast karstic plateau, that slopes gently down towards the Gulf of Asinara and the Nurra Plain.
Split into simpler sentences: Sassari is located in north-western Sardinia, at 225 metres above sea level. The area rises up on a wide karstic plateau, that slopes gently down towards the Gulf of Asinara and the Nurra Plain.