The patron saint of Assemini is Saint Peter the Apostle, celebrated on 29 June.
The parish church dedicated to him stands in the historic town centre: the original building dates from the first half of the 11th century, but underwent major changes when it was rebuilt in the 16th century in Catalan Gothic style, with a single nave and side chapels in late Gothic style, and again in the 18th century, when the squared and battlemented façade and the lower part of the bell tower were added. The municipal territory also holds the Monte Arcosu nature reserve and the Saline Conti Vecchi.
