epa-efeEl Alto, Bolivia

Hiring a prostitute in El Alto, Bolivia's second city, is a simple, hassle-free affair in which anything goes.

In a a visit organized by the Munasim Kullakita Foundation, which is dedicated to the protection of minors, EFE got a close-up look at the sordid underworld of prostitution in the 12 de Octubre neighborhood.

"La 12" (The Twelfth) is a few streets away from the highway linking this gritty industrial city to neighboring La Paz.

As night falls over the Altiplano highlands, as many as 19 brothels identified by Munasim Kullakita start coming alive.

Every night, La Casa Verde (The Green House) - one of the area's busiest brothels - welcomes a wide variety of males, from high school boys to old men looking for a quick and cheap hookup.

"It's sex on the spot; you go in and it's like it never happened," our guide said, reflecting the spirit of the place.

Inside the buzzing two-story establishment, loud music resounds as clients parade around, haggling over the price of sex before entering any one of the small doors surrounding the central dance floor.

Behind each door is a tiny space furnished only with a bed and a small table, outside of which countless men await to have sex with a prostitute.

Most women wait by the doorway wearing lingerie - or nothing at all - and while most of them appear to be in their 20s, our guide claims that "there is always a minor" of 17 or even 15.

The going price of a 20-minute session with a prostitute is between $6 and $8, which takes about the same time as a quick detour on the way back home from work would.

After Casa Verde, we made our way to a place that advertises that it has both Bolivian and foreign women, which has two dance floors, each one of which is surrounded by dozens of small rooms.

Off to a side, a group of men waiting in line outside one of the small doors stood out, and a waiter explained that it was because a "small, skinny and fine girl" had arrived.

Despite the fact that the place also has foreign women, men wait patiently for their turn with the youngest girls, as minors are thought to provide better sexual satisfaction and clients believe them to be disease-free, our chaperone said.

Demand for minors is such that they often lack the time to rest or wash up between clients, as they can receive as many as 20 clients a night.