Four Wells, or Cetiri bunara, is a 15th-century underground water-reservoir complex built to supply Sibenik during sieges and dry periods. The dry cisterns now hold Bunari - Secrets of Sibenik, a small multimedia exhibition space with displays on the city's history, food, shipwrecks, and notable figures.
It sits close to the cathedral and old-town lanes, so it is easy to add to a walk through central Sibenik.