But not all of them think the world will end today.
Many visitors are members of new age tour groups that focus on today as chance to have a spiritual awakening.
Mexico's federal government is not officially mentioning the phenomenon.
But the country's tourism agency launched a Mundo Maya 2012 website with a countdown to December 21st.
Earlier this year, a poll by Reuters University found that nearly 10 percent of people think the world will end sometime in 2012.