Motorcycles are the mode of choice for many people to get around in Medellín, Colombia. In the working-class districts that climb the steep slopes of the Valle de Aburrá, residents, often domestic migrants looking for work or fleeing violence, have self-built elaborate neighborhoods outside of formal urban planning. Narrow streets and alleys form the points of access, but while humans can walk up steps, wheeled vehicles require ramps. From the basic need to wheel your bike inside at night, a vast assortment of small ramps has emerged.

In the comunas of Medellín, these ramps are as common as doorways. Concrete is the material of modernism and high architecture, of buildings designed by and for the elite. But it is also the basic substance of self-built and self-organized structures in the developing world and of an architecture without architects.

These ramps, largely made without any consideration for their aesthetics, nevertheless possess a kind of sculptural and expressive quality, and constitute a kind of folk brutalism. Rampitas by Thomas Locke Hobbs (US) is a small study of and appreciation for these forms that tell so much about the conditions – social, economic, and topographical – that defined the struggles and lives of the people who built them.