 The deepest of these tunnels have revealed that the first monumental structures underlying the Acropolis date archaeologically to the early 5th century AD, when K'inich Yax K'uk' Mo' established the royal dynasty.These early buildings were built of stone and adobe and were themselves built upon earlier earth and cobble structures dating to the predynastic period.The two styles of building overlap somewhat, with some of the earthen structures being expanded during the first hundred years or so of the dynastic history of the city.