The Caracol camping trips that NICH is doing this year are mentioned on the New York Times. 'Mayan Sleepovers' are how they described them, and the Summer sleepover is next Wednesday night, the 20th of June. Email them for more information at email@example.com.
"...the sleepovers take place on solstice and equinox dates — June 20, Sept. 21 and Dec. 20 — at the site, in the country’s Cayo district. The stay begins with a pre-sunset tour led by Dr. Jaime Awe, who directed the excavation and restoration of Caracol in the 1980s... In the middle of the night, shamans wake campers with drumbeats, calling them to a Mayan fire ceremony, which lasts until dawn."
Via Best of Cayo