Cordoba was the capital of western Islam until the late 11th century and had the largest mosque in Europe. This great mosque -- known as La Mezquita -- is a breathtaking monument that juxtaposes Christianity and Islam. Wander through the Moorish columns bathed in golden light and picture how 40,000 worshipers would gather inside. In the center of this World Heritage Site, you’ll find an impressive Gothic cathedral, which was added in the 16th Century much to the chagrin of Carlos V who believed the mosque's integrity had been compromised. Today, visitors can learn about both cultures but take time for a quiet moment and marvel at this true architectural wonder. Admission is 8 Euro for adults, 4 Euro for children, and worth every cent.