When visiting Córdoba, you can’t miss the stunning Mezquita Catedral. This massive structure is the centerpiece of the city’s old town, and with good reason. It’s one of the world’s greatest Islamic buildings, demonstrating the brilliant architectural design and cultural influence they’ve had for centuries. Construction began in the 8th century when the Islamic kingdom ruled over Spain. When the Christians conquered the city in the 12th century, they elected to modify instead of demolishing it. You can notice the mix of Islamic and Christian design as you walk through the interior. Absolutely stunning. Enter for free from 8:30 to 9:20 a.m.