In Guatapé, every building is a work of art. Residents paint their houses and businesses in gorgeous bright colors, and decorate the bottom of every building with fresco-like panels called “zocalos.” It’s sometimes called the most colorful town in the world.

With its steep and windy streets and bright colors, Guatapé is ridiculously photogenic, but it’s the zocalos that make it distinctive. Some friezes are simply cute: Sunflowers, doves, and sheep are popular. Other zocalos advertise businesses: bread loaves on a bakery, sewing machines outside a clothing store. The most complicated tell stories—several panels showing a journey—or commemorate history: musical instruments marking the house of a famous local musician.

The zocalo tradition seems to have started about a century ago—no one seems sure when or why—but it has accelerated in recent years. Today it’s rigorously maintained because it helps make Guatapé one of the most popular vacation towns in Colombia, and a favorite day trip from Medellín, the city two hours to the west.

Guatapé is cheek-by-jowl two other Colombian wonders: It sits on the shore of a weird looking reservoir that twists and turns like a gerrymandered congressional district. And Guatapé is in the shadow of El Penol, one of the largest rocks in the world, climbable on an astonishing staircase.