Rising above a gritty swath of rail lines leading to and from the Porta Garibaldi Station in Milan, an eyecatching urban landmark has made another comeback from a state of disrepair. Studio Original Designers 6R5 Network, an almost 50-year-old local firm, joined forces with five partner companies, as well as the city council and Italian railway authorities, to restore vibrant tilework to the hourglass-shaped Torre Arcobaleno. The firm first revitalized the water tower in 1990, when Milan hosted the 14th FIFA World Cup, by adding colorful tile. It was an “old, worn, and ugly industrial artifact,” says executive associate Francesco Roggero, originally made of plain concrete and dating back to 1964. “We turned it into a point of reference, a vivid element in the hectic and active community of Milan,” says Roggero. Return­ing to the project 25 years later, in time for Expo 2015, the studio and its collaborators cleaned, replaced, or repaired all of the Rainbow Tower’s 11,000-square-foot surface. At 115 feet tall, the structure is covered in some 100,000 4-inch-square ceramic tiles in 14 colors, creating a pattern, says the firm, that “fits in with the new, feverish activity of the area.”