Hey, I'm Kelly McEvers, and this is embedded from NPR.

It is really hard to believe it's been 20 years since the United States invaded Iraq.

I'm sure you've seen the coverage of the anniversary, though I wish we had a better word for it than anniversary.

The remembrances and think pieces by Iraqis, American military folks, journalists like me who covered Iraq.

The story we have for you today, though, is different.

It's about something that happened in Iraq, that very first year after the invasion, 2004, when a bad thing happened, but was hidden from all of us.

Until now, my NPR colleagues Graham Smith and Tom Bowman will take the story from here.

Their series is called Taking Cover. Here's Graham and Tom.

Before we get started, you should know that this podcast contains graphic depictions of war, and we're talking to Marines, so there's a lot of cursing.

Camp Pendleton in Southern California is the West Coast home of the United States Marine Corps.

200 square miles of hills and wetlands and long stretches of beach just outside San Diego.

On its edge, there's a sharp hill covered with scrub trees and bushes that overlooks the Pacific Ocean.

It's called Hornow Ridge, and over the last 20 years, it's become a place of pilgrimage, where Marines sweat and suffer to honor their dead.

The hike up is steep and rocky, with two false summits, and at the top,

a small field of crosses and memorials, dozens of, of all sizes, some piece together from tree branches or lumber, some weighing hundreds of pounds.

Each one carried up by Marines and sailors.

Scott Rideski has climbed Hornow Ridge many times. There are hundreds, perhaps thousands, of keep-sakes and mementos.

I mean, everything from a coin to a wedding ring to a metal, a purple heart, to, I don't know, bottles of liquor that were poured out, a drink for their fallen comrade.

Rideski is a retired chaplain. He doesn't like the messy piles of empty bottles and cans, but he knows they're only part of what people leave behind on the ridge.

More important are the unseen burdens, the sorrow, the sadness.

The anger regret, who here's a big word shame, when someone dies and you don't, the grief that's their survivor's guilt,

and hopefully the lingering that takes place on the hill is part of that. You can move past the horrific things that you've maybe seen or done.

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