“It's unbelievable to be here!” said Stafford the moment he entered the sea. “It proves you can do anything — even if people say you cannot. I've proved that if you want something enough, you can do anything!” A few hours earlier, Stafford had collapsed at the side of the road, just short of his destination. But upon arrival at the Maruda beach — and his journey's end — Stafford looked like he had all the energy in the world, as if walking for 2 years were nothing as he jumped into the ocean and hugged anyone in sight.

While he says he is “no eco-warrior,” Stafford said near the end of his journey that he hoped his feat would raise awareness of destruction to the Amazon rain forest — but that at its heart, it was simply a grand expedition of endurance.

“The crux of it is, if this wasn't a selfish, boy's-own adventure, I don't think it would have worked,” said the 34-year-old former British army captain as he sat under the Brazilian sun near the jungle city of Belem.

“I am simply doing it because no one has done it before.” There are at least six known expeditions along the course of the Amazon River, from its source high in the Peruvian Andes across Colombia and into Brazil before its waters are dumped into the ocean 6,760 kilometers away.

But those used boats to advance their travel.

Stafford and a British friend began the walk on April 2, 2008, on the southern coast of Peru. Within three months, his pal left. Stafford carried on, walking bits of the route with hundreds of locals he met along the way.

Eventually, Peruvian forestry worker Gadiel “Cho” Sanchez Rivera, 31, decided to make the journey with Stafford to the Atlantic.

Stafford said his journey — which has cost $100,000 and is paid for by sponsoring companies and donations — has deepened his understanding of the Amazon.

He has lived off piranha fish he caught, rice and beans, and store-bought munitions found in local communities along the river.

To relax at night, Stafford said he has downloaded podcasts via Internet satellite phone by British comedian Ricky Gervais and episodes of the TV show “The Office.” Stafford and Rivera have encountered every conceivable danger, from 5.5-meter long caimans, enormous anaconda snakes, illness, food shortages and the threat of drowning.

After they were welcomed in one Indian community in September 2008, the leaders offered to radio ahead to the next village for permission for Stafford and Rivera to walk through their territory.

“The response came back crystal clear. If a gringo walks into their community they will kill him,” Stafford wrote on his blog at that time.

He decided to plan a route around the village, but he was still captured by Indians from another village and taken to their leaders.

After being dressed down and having their possessions thoroughly picked over — only a machete was confiscated — Stafford and Rivera's repeated explanations of the point of their expedition won over the Indians.

They were allowed to walk on the land, but only if they hired guides from the tribe.

Stafford said he plans another expedition in September 2011 — something nobody has ever done — but will not provide details for fear someone might beat him to it.

Until then, a good, long rest awaits.

“This expedition has been our lives. For 2 years we've done nothing but walk and walk and walk. To wake up the morning after and know that we've done it will be a big change,” said Stafford. “I think we'll get used to it though.”