This is 99% invisible. I'm Roman Mars.

Here's something you probably didn't know about Mumbai, India.

There are about 55 acres of dense overgrown forest right downtown.

In one of the most populous cities in the world, this is a place where peacocks roam freely,

a place that seems to peel back centuries.

This forest is protected by a religious community.

It is survived undeveloped in the middle of this gargantuan city.

Importantly, it's also home to an ancient tradition that's in crisis.

One of our producers, Loshamadon, traveled there in September.

I turned off a busy road to get here, stepped through a large iron archway and up a small hill.

The monsoon's long gone, but the air still feels heavy with moisture.

Behind me, tall buildings shimmer in a haze of pollution. And up ahead, I see a

sprawling expanse of green. This forest is called Dungurwadi.

As you step in from the harsh sunlight and road outside,

you just step into an extremely quiet place.

This is Rush Nip Bardihuahala,

someone who grew up in Mumbai

and knows this place intimately.

You can hear the dry leaves rustling below your footsteps. The forest is dark and deep.

There are different trees in bloom, wild banana, mango, jackfruit, tamarind. I saw one whole tree just covered with fruit bats,

chittering away. The vegetation here is dense.

It's so thick you've got to bend, you've got to see where you're stepping.

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