Complex sentence: The name comes from the roman word "Villa Azari", later changed to "Vilassar", splited in the 20th century in two villages one up the hills (de Dalt), and one by the Sea (de Mar).
Split into simpler sentences: The name comes from the Roman name "Villa Azari", later changed to "Vilassar". Vilassar in the hills (de Dalt), and Vilassar by the Sea (de Mar).