Scientists have discovered the largest and oldest-known structure that was built by the ancient Mayan people. Large and shaped like a rectangle, the structure was built between 2,800 and 3,000 years ago in what is now the Mexican state of Tabasco. Unlike the large Mayan pyramids built some 1,500 years later, the newly discovered building was made with clay and earth. It was likely used for ceremonies, researchers say. Built near the Guatemalan border, the structure measured nearly 400 meters wide and nearly 1,400 meters long. It stood between 10 and 15 meters high. It had more volume, the amount of space, than Egypt’s Great Pyramid of Giza.