Full coverage: 80th Anniversary of the Victory of the Red Army's Long March

This year marks the 80th anniversary of the Long March. The Red Army soldiers who were swept up in the strategic retreat fought, starved, and persisted. It was one of history’s greatest journeys, and today on this Martyrs' Day, our reporter Tao Yuan takes us back for a look at the worst part of the Long March.

This was the hardest stretch of the Long March, the most painful with the greatest losses.

It seems peaceful here -- no enemy soldiers, no enemy planes. Nothing but quiet nature.

It was like another world. There were no people, no houses, no roads -- just grass, grass up to the horizon, empty of everything.

But during the Long March, these grasslands hid miles and miles of treacherous swamp. For China's languishing troops, every step was dangerous.

Gong Chan’s father was one of the soldiers, who never made it out.

"It was hard to tell the swamps from grass. The troops didn’t have enough oxygen, didn’t have enough to eat. They reached their limit. My father said he watched his comrades sink into the swamps. the more they struggled to get out, the faster they sank. It was impossible to pull them back up," Gong said.

The marching troops were low on food. They largely relied on wild herbs. When that was hard to come by, they killed what few horses they had left. And when that meat ran out, they boiled their leather belts or shoes to fill their stomachs.

We fought hunger and fatigue non-stop. Many comrades suddenly fell over, and never got back on their feet again.

There’s no official account of how many people died, but unofficial estimates put the figure at more than ten thousand.

A soldier named Wang Ping, who would later become one of China’s founding generals, was tasked with retrieving the troops that fell behind.

I inspected the other side of the river with a telescope and saw at least seven to eight hundred men. When we crossed the river, we found them just sitting there, back to back, not moving in the slightest. We inspected them one by one, none were breathing. I couldn’t hold back my tears. (pause a second) We laid them down, to make them more comfortable, and to check for anyone alive. At the end, we found a young comrade breathing. I had a soldier carry him on his back. But after we crossed the river, he died, too.

The troops spent seven days marching through the swamps. On the last day, the rain suddenly stopped, and a beam of sunlight broke through the sky.

It was as if to welcome us lucky ones who escaped hell alive. We stood on solid ground. We smiled.

We saw villages, people, yaks and sheep and smoke, and big turnips in the fields. Looking back at the seven days, I felt like I was reborn.