Banteay Chhmar, Cambodia - It's hot and I have a headache.

The sun is too bright and reflecting off the corrugated tin roofs of tiny shops. And there are so many people, it is dizzying.

Everywhere you look, throngs of people walking from home to store, store to home, milling around street vendor carts, begging for change, or sitting on plastic chairs by the side of the road silently watching it all unfold.

Sitting in this backseat of a cramped crew cab pickup truck, I'm sharing with two other guys, our backpacks, and a 16 kilogram camera.

It's 33 degrees Celsius and I'm told it's winter: The end of the rainy season. I can't imagine it could be any worse than this, so I ask our Cambodian driver what it's like here in the summer.

He looks at me through the rear view mirror.

"Hotter," he replies, focusing his smirking eyes back on the road.

No matter how tropical or humid the climate, dry humor exists everywhere.

Out the window, I see there are far too many people on the road and too many types of vehicles. Bicycles. Bicycles with motors rigged up to their frames. Motorcycles. Motorcycles with carriages rigged up to their backs. The Cambodians call those tuk-tuks: their equivalent of a taxi. Toyota Camrys and well-worn Nissan pickups. All fighting for space on the road with the cattle and chickens and men and children and women carrying woven wicker baskets on their heads.

There are no stop-lights, no stop signs. No rules or order to the roadway that I can make out, except that if you are going to pass, you have to honk.

A man on a motorcycle weaves around an old piece of farm equipment plodding down the road, then swerves awkwardly to avoid an oncoming car. The man's wife and two small children clutch on to each other's clothing, to avoid being thrown off.

It's all too much. I look in my backpack for a bottle of water. All the activity is making me nervous and nauseous.

Some of my crankiness can be attributed to the fact I'm just a few hours removed from an arduous 17 hour trans-Pacific flight that started in Atlanta, crossed the Arctic Circle, dropped me off in Seoul to catch my breath and stretch my cramping legs, and then carried me on to Siem Reap.

We're going to be here for the next 10 days shooting a documentary on human trafficking and the personal impact it has on the lives of families. Before we do that, though, we're taking a side trip to a place called Banteay Chhmar, to file a story about climate change and the effects it can have on a civilization.

Banteay Chhmar is the kind of place I didn't think still existed on Earth. An ancient ruin, it's discovered but still unknown. Built in the 12th century by the great Khmer ruler Jayavarman II, today it sits empty. Historians still don't know why the city was built or why it was abandoned. It's hard even to understand why it's still here. Just a few meters from a village with the same name, there are no tourists, no squatters and very little evidence that there ever have been.

There are only a few dozen local laborers who, under the supervision of project leader John Sanday, are working to restore the site to the point it's safe and attractive to outside visitors. The hope is, they'll be able to train locals to set up a responsible, sustainable tourist industry, where the money goes to members of the local community, not foreign investors from countries like South Korea, the United States, China, or Japan.

The city was abandoned more than 500 years ago. Sanday, who is an architect by trade and lives in Katmandu, is our guide. He tells us that scientists believe that changes in the climate coupled with political instability and an aging infrastructure. He surmises that a period of prolonged drought created water scarcity, food shortages and unrest, which forced the royal family to move south to the area which is now Phnom Penh.

When that happened, like the city's reservoirs, its wealth and economic energy also dried up.

As our truck rambled into the site, we turned onto a pathway that crossed over that same reservoir. Two giant Buddha heads made our welcome at the entrance.

I was amazed they were still there. Two minutes later we were in the main part of the city. Now I was shocked. To me, it felt like re-entering a city that had been evacuated during a bombing raid. Sanday led us around, pointing out why this gate was important, why rulers had created that massive bas relief to show their power, and how this structure had been felled by the roots of a tree. Everywhere you looked were piles of rubble. It went on for hundreds of meters in every direction.

There were large courtyards where only pillars remained. Huge rooms that opened to the sky and jungle canopy. Intricately carved doorways stood, upright and exposed, while the wall that had encased it lay in a heap. Each time you rounded a corner, or even turned your head, there was something new and breath-taking to look at and take a picture of.

My favorite part of the city, though, were faces of the Buddha, carved seamlessly into the towers of the temples, looking out over all of it. A precursor to the architecture you see on the Bayon Temple at Angkor Wat, the entire time we were there they seemed to be looking down at us, smiling knowingly, as we explored their city and pointed our cameras up to take their picture.

We spent two days there, bounding over the ruins, looking at the incredible art and architecture, taking pictures and discussing what led to the collapse of this once-powerful civilization.

When it was time to leave, and we crawled through to the old corridor made dark by dusk's fading light, I thought about the people who passed through these hallways so many centuries ago. I thought how interesting that, thanks to the potential tourism industry, their hard work then, might now bring about a new dawn in the lives of their descendents.

And as we packed into pick-up for our long ride back to Siem Reap, I was struck by another thought and smiled.

This was definitely worth the trip.

It’s a rare story that captures a journalist’s imagination the way this one has.

I first heard of El Mirador from Jeff Morgan, the founder of the Global Heritage Fund.

We were talking about his organization when he mentioned this ancient Mayan city they were working to save. Buried deep in the jungles of Northern Guatemala are the stone relics of an empire. His voice cracked with enthusiasm as he described the amazing discoveries being unearthed almost daily.

The archeologists excavating there say they have evidence now showing Mirador, this remote site almost no one has ever heard of, is home to the largest pyramid in the world by volume, the first freeway system in the world and a newly unearthed piece artwork, the size of a football field, that could rewrite the historical timeline of the Mayan civilization.

As a journalist, I did what I’ve been trained to do and asked calmly, “I’m sorry, can you repeat that?”

He did, so my follow-up question was easy: “How can we get there?”

We arrived by helicopter from Guatemala City along with Morgan and the director of the Mirador Basin Project, Richard Hansen. When you’re in the jungle for the first time, a couple thoughts cross your mind. First, you wonder what else is out there, lurking behind the brush and branches, sizing you up.

And the second thing you think about is where you put your water. The heat is intense. It was 34 C the whole time we were there – day and night – and moisture from the jungle canopy adds a steamy, sticky film to your skin that traps the heat.

Our shoot lasted several days, short by documentary filming standards, but we packed in as much work as possible. Working 14-hour days, we hiked for miles, scaled pyramids, squeezed through tiny corridors to get inside the temples.

But in addition to all the wonderful historical discoveries, there is another, more pressing reason we went to film this story. Mirador is facing threats on several fronts.

Looters are constantly breaking into the sites and stealing priceless artifacts. Loggers and cattle ranchers are cutting down the surrounding rainforest at an alarming speed. And narco-traffickers, flying cocaine-filled planes, are landing in the remote areas then setting them ablaze, sparking devastating wildfires.

For Jeff Morgan, Richard Hansen, and several organizations like PACUNAM and APANAC, the purpose of saving and preserving this incredible site is so that the people who live in the surrounding villages will benefit.

These groups hope that by creating a sustainable tourist destination, it will attract tourists from around the world, and bring badly needed fund to the poorest area of the country.

Looking back, it felt like a whirlwind going from plane, to helicopter, to isolated jungle and then back again. But I came away from the experience with the sense that there are still wonders left in this world to be discovered, and good people fighting with everything they have, to save them.

It’s a story I’ll never forget. And one that I hope, for the archeologists and people of Guatemala, has a happy ending.