Choose the most correct answer. The following text is for questions number 14 to 5.

    The Yucatan is in Peninsula. It's just into the western Caribbean Sea. The Yucatan is the site of many impressive Maya ruins. Many of the ruins are amazing, but it is Chichen Itza. Chichen Itza is perhaps the most amazing. Chichen Itza was the most important city in the Peninsula from the 10th to the 12th century.

    Chichen Itza filled with structure. These structures are enormous and awe inspiring. For example, at Chichen Itza is an impressive Ball Court. Its acoustics are phenomenal. In fact, the acoustics of the Ball Court still baffle scientists and musicians. Scientists and musicians have spent long hours analyzing its construction. Dominating ruins is the famous 98-foot-tall El Castillo pyramid. El Castillo is the most impressive monument in Chichen Itza. El Castillo is a masterpiece of Toltedo-Maya architectural design and genius.

The passage is mainly talking about ____.