Florida.

Founded on the northern Atlantic coast of Florida in 1565 by Pedro Menendez de Aviles, San Agustin de la Florida was the first Spanish settlement and the oldest European city in the United States. As the capital of Spain's colony of Florida for more than 250 years, the city was the site of important military fortifications. The colony had an adventurous history. In 1763 Florida became the property of England, passing back to Spain in 1783, to be ceded to the United States in 1819. The Spanish colonial city was loosely organized into a grid of streets centered on a main plaza, a type of urban planning popular in sixteenthcentury Spain, with its roots in ancient Rome. The Spanish relocated the city twice, in 1566 and in 1572, and in the seventeenth century its population grew dramatically.

Castle of St. Mark.

Because of its position on the coast, the...