NARRATOR: The Himalayas, Northern India.
Every summer, hundreds of thousands of Hindu pilgrims
brave an arduous journey.
They cross many miles of deadly terrain
to reach the Amarnath Cave, a place of worship
for thousands of years.
12,756 feet above sea level in the Himalayas
is the most revered holy pilgrimage
site for all of the people who follow the Hindu faith.
DEEPAK SHIMKHADA: People die because of high altitude
sickness or they just simply fall off the cliff,
and still people who go there because it is considered
to be the most holiest shrine.
NARRATOR: According to local lore,
this massive cave is where the god Shiva revealed the secrets
of immortality and the creation of the universe
to his wife Parvati.
[shouting]
To honor Shiva, worshippers pay their respects
to a sacred relic inside, an ice lingam, which they believe
is a physical manifestation of his generative power.
To reveal the secret to transcending the flesh,
the secret to true immortality, makes
that site of extreme importance to the people
in the Hindu faith.
NARRATOR: To the Hindu faithful who risk life and limb to reach
the Amarnath Cave, this story is a real account
of an otherworldly being, who was at this exact location
here on Earth.
But could the enlightenment found inside caves
be coming from an extraterrestrial source
inside the Earth?
Some ancient astronaut theorists say yes
and suggest evidence of this might be found
in the fabled nirvana known as Shambhala and the Sky
Caves of Mustang in Nepal.
Some say Shambhala is a mythical city
that's located somewhere in the mountains in the Himalayas.
Its inhabitants are supposed to be fully enlightened beings who
have access to a great amount of technology, which comes
from the enlightenment itself.
Buddhism has always seen caves as more or less a conduit
to altered states of consciousness,
to other civilizations that may exist inside the Earth.
[music playing]
The sky caves in Mustang are interesting because there are
a hundreds or so man-made caves carved into the faces
of cliffs, and they're only accessible
by these huge vertical shafts.
And inside these caves, we have huge statues
of Buddhas, bodhisattavs.
NARRATOR: And Buddhists are not alone in this belief.
Hindus also revere caves as places where
monks can go to find wisdom.
The sadhu are Indian holy men who basically leave a life
of deprivation, a self-imposed exile in caves,
so that they can enter these altered state of consciousness.
They definitely believe that caves
are a conduit to communicating with non-human entities.
It's almost as though they're opening a doorway
to a spiritual consciousness in which they're
able to communicate with these divine beings
and hopefully become divine themselves.
[music playing]
NARRATOR: Why are there so many accounts
of humans having enlightening experiences inside caves?
Is there something about caves themselves that facilitate
such extraordinary experiences?
Could it be that these people are
coming into contact with an extraterrestrial presence?
Ancient astronaut theorists suggest
that cosmic knowledge may be stored in the very walls
of these caves themselves.
I don't think that this is a coincidence
that places of refuge, spiritual refuge, are inside caves.
This is where one can contemplate,
one can hear one's inner voice without the distractions
of the day.
One thing about caves is they're underground.
They're unseen.
Well, religion is about unseen things.
Going into a cave is going into holy ground.
[music playing]
If we are looking for extraterrestrials,
ironically, the heavens above might
not be the best place to look.
We should perhaps even be looking deep below our feet.
In some ways, exploring the underground
cavern world of planet Earth is-- is the final frontier.
[music playing]