City Walls & Forts – No visit to Dubrovnik would be complete without a walk around the spectacular city walls, the finest in the world and the city’s main claim to fame. The first set of walls to enclose the city was built in the 9th century. In the middle of the 14th century the 1.5m-thick defences were fortified with 15 square forts. The threat of attacks from the Turks in the 15th century prompted the city to strengthen the existing forts and add new ones, so that the entire old town was contained within a stone barrier 2km long and up to 25m high.

Sponza Palace – This superb 16th-century palace is a mixture of Gothic and Renaissance styles beginning with an exquisite Renaissance portico resting on six columns. The 1st floor has late-Gothic windows and the 2nd-floor windows are in a Renaissance style, with an alcove containing a statue of St Blaise. Sponza Palace was originally a customs house, then a mint, a state treasury and a bank.

Franciscan Monastery & Museum – Within this monastery’s solid stone walls is a gorgeous mid-14th-century cloister , a historic pharmacy and a small museum with a collection of relics and liturgical objects, including chalices, paintings, gold jewellery and pharmacy items such as laboratory gear and medical books.

https://www.lonelyplanet.com/croatia/dubrovnik

….and much more