with a very special ingredient --

a nest of the swiftlet bird.

Narrator: The soup is considered a delicacy

around the world.

One bowl can cost as much as $100.

Harvesters have to climb slippery cliffs

just to find and collect the coveted nests.

We went to the Philippines to find out

how this infamous dish is prepared

and why it's such a rare treat.

Meet Robin Palacio Jr.

He's a chef at Liedans, a restaurant here in Taytay.

Narrator: Lomi is a traditional Filipino soup

made with egg noodles, meat, and vegetables.

Preparing it is simple.

You start by simmering some garlic and onion in olive oil.

Then, Chef Robin adds veggies and noodles

before the swiftlet nest goes in.

It only takes about 45 seconds for the nest to cook.

And he adds some of the nest in the end as garnish.

The nests are rich in protein and amino acids.

And they cost between $1,000

to $10,000 per kilogram, depending on the quality.

Narrator: Gathering the main ingredient requires

years of experience.

Alvin Villarendo climbs cliffs

that are up to 100 feet high

with no harnesses or safety gear.

Narrator: The men in Alvin's family have been doing

this job for generations.

Their ancestors discovered the caves on Nabat Island

hundreds of years ago.

Now they're the only ones allowed

to pick the nest during harvest season

between December to April.

Alvin can find as many as 2,500 in those five months.

Locals also believe in the healing power

of bird's nest soup.

Narrator: Alvin's wife, Marbie, drank it

after giving birth.

Narrator: Studies show the soup is high

in sialic acids, which improve neurological

and intellectual function in infants.

And here in the Philippines,

people claim it has other health benefits, too.

Narrator: While those claims haven't been proven,

the soup is still a favorite in China, Indonesia,

and among locals in the Philippines.