Archaeologists have discovered an "incredible" treasure trove of artefacts in a cave underneath Mexico's most famous Mayan ruins.
The Balamku cave was first discovered more than 50 years ago by locals in the ancient city of Chichen Itza, but the official sent to investigate mysteriously sealed off the entrance with stones, and the site remained unexplored.
Balamku means 'jaguar god' in Mayan - but researchers had to contend with another dangerous animal to gain entry to the cave.
The indigenous Mayas who live in the area warned the team from Mexico's National Anthropology and History Institute (INAH) that a venomous snake guarded the site.
They found one at the entrance, which blocked their access for four days.
After performing a six-hour ritual at the locals' behest, the team were finally able to enter the cave.
To reach the chambers they had to navigate narrow connecting passages, sometimes crawling because the gaps were so tight.
In the depths of the cave they found a "scientific treasure," Mexican archaeologist Guillermo de Anda said.
They found incense burners and vessels containing among other things carbonised remains of food, seeds, jade, shell and bones that the ancient Mayas offered to their gods.
Hundreds of artefacts were in "perfect condition".
The team has explored around 460 metres of the cave so far, and they do not yet know how far it stretches.
The site is located 24 metres underground, around two kilometres to the east of the pyramid known as 'El Castillo' or Kukulkan.
Chichen Itza, the Mayan city which dates back to around 600 AD, is located in Mexico's Yucatan peninsula.
Experts say the Balamku cave is the most important discovery in the area for more than 60 years.
