A few years ago, they started excavating in downtown Sevilla to build a much needed underground parking, and found: treasure!!! Ancient ruins from the Phoenicians and Romans dating back more than 2000 years! Among them, beautiful tile floors of ancient homes, workshops, etc. They built a very modern, interactive museum with their findings instead of the proposed parking space.
This is the most comprehensive collection of archaeological treasures from this city. I strongly recommend visiting it. It is underneath "Las Setas", a modern structure in the shape of mushrooms, in front of Plaza de la Encarnacion, downtown Sevilla.