The National Museum, in Bogotá, is holding a colorful exhibition about Colombia's 14 UNESCO World Heritage sites, which include both cultural and natural phenomena. These include very concrete things, such as the Coffee Region and carnaval parades, as well as immaterial phenomena such as music and indigenous peoples' traditional knowledge.

While most of Bogotá's art galleries are located in the Zona Rosa and Macarena neighborhoods, the last few years more galleries have opened in La Candelaria, the city's historical center.

They've been called ghosts, memorials to the dead, even visiting extraterrestrials. They are the green men (and a few women) standing on rooftops and balconies in La Candelaria. They include a model, a shoeshiner, an acrobat, a musician (without his guitar) and others of unclear profession.