A Neo-Baroque palace that once housed the central post office and telecommunications service, the Palacio de Cibeles became Madrid’s City Hall in 2007. Even the city councilors didn’t need something this big, so much of the building has been converted into a series of galleries, a concert hall, and other public spaces called CentroCentro. There’s a reading area with daily papers and free Internet access, a tourist information office, and a top-notch restaurant (Restaurante Palacio de Cibeles) as well as more casual cafeterias. But the main reason for visiting is the Mirador Madrid. An elevator whisks you to the seventh floor, where you can walk around on an open-air balcony for some of the best views of the city.