The Netherlands is small --
smaller than West Virginia --
and the most densely populated
country in Europe.
Most of the country
is below sea level,
reclaimed with great effort over
many generations from the sea.
That's why they like to say,
"God made the world,
but the Dutch, we made Holland."
This is polder land.
Much of it once covered
by the sea,
it was encircled by dikes
and dams and then drained.
To pump out all that water,
the Dutch used one of their
leading natural resources --
the wind.
For centuries,
the Dutch built windmills.
Over a thousand survive,
and many still work.
Some welcome visitors
interested in a peek at
the clever engine
that powered the creation
of this land.
I'm standing on reclaimed land,
12 feet below sea level.
The challenge for the Dutch --
to keep this land dry
by pumping water uphill.
Many windmills
used their wind power
to turn an Archimedes' screw,
like this,
which, by rotating in a tube,
lifted water up
and over the dike.
To catch the desired
amount of wind,
millers, like expert sailors,
know just how much to unfurl
the sails --
or furl them back,
as necessary.
Mills are built with sturdy
oak timber frames
to withstand
the constant tension.
These timbers have stood strong
since the 1600s.
When the direction of
the wind shifts,
the miller turns the cap
of the building --
which weighs many tons --
to face the breeze.
As he spins the winch,
it all slides on these
wooden roller bearings.
Then, with a hefty chain,
he anchors it
in the correct spot.
As the wooden cogs connect,
wind becomes
clean power,
Archimedes' screw rotates,
and the water spirals up.
The Dutch had long eyed what was
the vast inland Zuiderzee
as a source of new land.
This 18-mile-long dam was built
as one of many steps
in turning that sea
into farmland.
The master plan --
cordon off sections of
the shallow sea
with hundreds of miles of
dams and dikes like this.
Then, by draining
each section dry,
piece by piece,
build a bigger country.
These fields were once
the bottom of that
wide-open sea.
Gradually,
land was reclaimed,
and today the Netherlands is
twice the size
it was 400 years ago.
Because of this reclamation,
what had been fishing villages
on little islands --
like Schokland --
are now high and dry mounds
rising above fertile farmland.
Behind this sturdy
stone-and-wood seawall,
this tiny community
once harvested the sea.
In its day, this cannon warned
visitors of a high tide.
I'm standing below sea level.
I know that because I picked up
a handful of dirt
and it came with some shells --
and this marks sea level
according to the official
Amsterdam measure, zero.
Imagine, a couple
generations ago,
this buoy bobbed in the harbor.
What was the bottom of the sea
is now productive farmland.
