While most 15-year-old boys are on their way to school in the morning, Julio Cesar Gutierrez is on his way to work.
He toils inside the Cerro Rico, or "rich mountain" of Potosí, for the fabled Bolivian silver that looms at the peak at the Andes mountains, dominating every view of the highest city in the world. It is the oldest mine in the Americas and one of the oldest working mines in the world.
It is also one of the most dangerous.
The entrance to the mine is muddy, with a sloping ceiling. At 15,000 feet above sea level you have to work to take in each breath.
Gutierrez took ABC News into the mine with his older brother Luis Alberto and some other boys. It was a daunting tour inside what truly is a hell on Earth. An estimated 20,000 people work each day, including 1,000 children.
Inside there are no lights except for the workers' head lamps, and there is no ventilation, or safety equipment. Often there is just one exit; if a shaft collapses there is no way out.
Gutierrez began working outside the mine when he was just 6 years old; he's been working inside since he was 12.
"I hate it," he said in Spanish. "It's very dangerous for children."
Potosí may be the most important place in the history of the modern world that most people have never heard of. The Spanish discovered silver in Potosí in 1545. The mine was so rich that historians say its wealth single-handedly fueled the Spanish conquest of the Americas. They call it "The Mountain That Eats Men."
It is estimated that 8 million American Indian and African slaves died in forced labor at the mine. Amid the colonial remnants of what was once a magnificent city sits the massive Spanish royal mint, now a museum that shows just a fraction of the mother lode that made this remote mountainous place the largest city in the world by the year 1650. And the richest.
And yet all that is left behind is poverty, a poverty of such extreme desperation that it sends men and boys into the 400 mines burrowed into the mountain's belly to scratch out the most meager of livings.
While technically the mines are owned by private companies, in reality there are no owners. They are run as cooperatives.
Fernando Vasquez, director of social management for Bolivia's Cooperative Mining Sector, told ABC News the coops need a lot of investment to improve safety conditions.
In this, the poorest country in South America, there are no safety inspections of mines. The government does, however, provide guidelines and seminars to promote safety.
In the end, Vasquez says safety is solely the responsibility of each mining company or cooperative, which is why what we saw inside looked almost medieval: no safety gear, no power, no ventilation.
The boys told us to run through one section with broken beams overhead, knowing it could collapse at any moment. We heard the distant sound of drills as we wound our way through the snaking tunnels and narrow shafts.
John Trew, senior technical adviser on child labor at the charity CARE USA, traveled to Potosí to talk to us about CARE's work there. He has traveled the world studying child labor and trying to improve conditions for children, and he is horrified by what he sees here.