Bill Benenson, the filmmaker who financed the search for the lost city, exploring the unnamed river in the valley of T1 below the ruins.

Dr. Alicia González, the expedition’s anthropologist, in the Mosquitia jungle, 2015. In the background, from left to right are: Chris Fisher, Anna Cohen, and Andrew Wood.

Chris Fisher exploring the ruins using a Trimble GPS. This photograph was taken in the main central plaza of the lost city, surrounded by mounds and an earthen pyramid. The incredible thickness of the jungle obscured everything.

The “kitchen” area of the expedition’s camp deep in the Mosquitia jungle, 2015. The area was so remote, the animals apparently had never seen people before and wandered about, unafraid.

Honduran TESON Special Forces soldiers accompanied the expedition; they are roasting a deer over the fire in their camp, 2015.

Oscar Neil, chief of archaeology for Honduras, discovered the first altar stone in the ruins a few seconds before this photo was taken in February 2015. The altar is barely visible behind his right hand; it proved to be a large, flat stone placed on three quartz boulders, in a long line of altars alongside the main plaza of the city.

The cache or offering of stone objects, vessels, thrones, and figures, with just the tops visible above the surface of the ground. The excavation of this cache would solve one of the greatest mysteries of this enigmatic civilization: What caused its sudden, catastrophic disappearance five centuries earlier?

The were-jaguar as it first appeared emerging from the ground. Photographer David Yoder risked his life to climb up to the cache at night to photograph the artifacts using a special “light-painting” photographic technique.

Archaeologist Anna Cohen excavates stone vessels at the site of the mysterious cache. Visible here is the so-called “alien baby” stone vessel, which may depict a corpse bound for burial, a captive awaiting sacrifice, or a half-monkey, half-human deity.

The mysterious sculpture placed in the center of the cache found at the base of the central pyramid, which archaeologists believe depicts a shaman in a spiritually transformed state as a vulture.

Deforestation on the way to the valley of T1, primarily clearing land for cattle grazing. One Honduran official estimated that illegal clearcutting would have reached the valley of T1 in fewer than 8 years. The expedition and its discoveries, however, motivated the Honduran government to crack down on deforestation in the Mosquitia region.

President Hernández of Honduras and Steve Elkins after his arrival by helicopter at the site of the lost city, 2016.