Tikal is the site of a major Mayan civilisation that dates back to the 6th century BC. I arrived in a small group at 4am in order to climb one of the tallest of these ancient pyramids for sunrise. We sat for perhaps an hour, perched above the jungle canopy in the dark, listening to the eerie roar of howler monkeys near and far. We saw no sunrise, the humid jungle shrouded in mist.