At the heart of the Italian boot-heel, Monopoli takes full advantage of its place on the Adriatic, with plenty of beaches at its southern end that include Lido belli freschi and Purple Beach, both of which attract a ton of people from the area both for swimming, sunning, and a happening nightlife. Cala Porta Vecchia is a conveniently located beach just off of the old harbor, a picturesque collection of buildings that date back centuries that overlook a cove often teeming with fishing boats. The main coastal landmarks are the thousand year old castle of St. Stephen, located just to the southeast, and the Castle of Charles V, a central fortification nearly five hundred years old that also has a promenade on the waterfront.
Head out of town toward Savelletri for the site of the Egnazia Ruins, whose original city walls have withstood millennia, while a city's worth of half-standing pillars and foundations also remain. You can also do a little light hiking on the nearby Monte San Nicola.