Municipality of Mérida
Mérida, the capital of western Spain's Extremadura region, was founded by the Romans in the 1st century B. C. Remains of the ancient city include the still-used Teatro Romano, which has a double tier of columns rising onstage. The ancient Puente Romano, a 792m bridge spanning the Río Guadiana, adjoins the Alcazaba, a 9th-century Islamic fortress built over Roman walls.