Experts have discovered a third structure within the Kukulkan pyramid in eastern Mexico revealing that it was built like a Russian nesting doll. A 10 metre tall pyramid was found within another 20 meter structure which itself is enveloped by the 30 metre pyramid visible at the Mayan archeological complex known as Chichen Itza in Yucatan state. The smallest pyramid was built between the years 550 and 800 .The middle structure had already been discovered in 1930s and dates back to the years 800-1000 while the largest one was finished between 1050-1300.The discovery suggests that the pyramid known as El Castillo was built in three phases. The structure was built on top of each other for various reasons including deterioration or the arrival of new leadership. The smallest pyramid was spotted using a non-invasive technique that consists in lighting the insider of the pyramid to see its interior without causing damage. The discovery could shed light on the original Mayan culture before populations from Central Mexico influenced it.