Paso Yobái is one of Paraguay's most unusual places: a yerba mate district where, since the mid-1990s, small-scale gold mining has reshaped both the economy and the landscape. In its rural communities, yerba plantations, small mining operations and an industrial concession sit side by side. For visitors, the best time is August, with the patron-saint feast on the 15th and the Itaju Festival, famous for raffling off chests of rocks containing gold nuggets. It's also a window onto the environmental dilemmas of mining in the country.

It was founded on April 20, 1923, as an agricultural colony by Swiss businessman Jorge Naville, on land previously inhabited by the Mbya Guaraní. Yerba mate drove the local economy for decades, hauled to Villarrica in ox carts. In the mid-1990s gold was discovered by chance and artisanal mining took off; today it employs about a quarter of the population, amid heated debate over the use of mercury and cyanide.