One of the great medieval monuments in the Mediterranean, the walls of Rhodes are wonderfully restored and illustrate the engineering capabilities as well as the financial and human resources available to the Knights of St. John. For 200 years the Knights strengthened the walls by thickening them, up to 40 feet in places, and curving them so as to deflect cannonballs. The moat between the inner and outer walls never contained water; it was a device to prevent invaders from constructing siege towers. You can get a sense of the enclosed city's massive scale by walking inside the moat.
Parts of the walkway that runs the 4 km (2½ miles) along the top of the walls is sometimes accessible for an extra fee to visitors to the Archaeological Museum and to the Palace of the Grand Masters; access is through the Palace of the Grand Master. Hours vary, so check with one of the sights or the tourist office.
Old Town, Rhodes Town, Rhodes, Greece