In Bolivia, almost a decade after the election of Evo Morales, the country’s first indigenous president, the economy is enjoying a natural-gas-fueled boom that’s unprecedented—both in its scale and the participation of native groups. That’s on display vividly in El Alto, a city of 1 million near the border with Peru. Vibrant homes are sprouting up, expressing the good fortune and cultural pride of the Aymara people, as well as the flamboyant vision of architect Freddy Mamani. His intricately detailed buildings have injected color into this drab city, which at 13,615 feet is the highest in the world. Bolivia’s old money dismisses the towering structures as nouveau riche eyesores, but foreign critics are hailing a New Andean Architecture.