The close-in neighborhood called Colonia Roma was first developed at the dawn of the 20th century as a high-end suburb laid out along tree-lined boulevards and plazas. Prominent families erected elaborate residences in architectural styles ranging from neoclassical to art nouveau and even neo-Moorish. A century later—despite some ups and downs—the district is at a peak as one of Mexico City’s most fashionable areas, and old mansions now serve as retail spaces or smart dining rooms that open out onto the street, day and night, in that marvelous dolce vita way. Stroll the quarter’s main drag, Álvaro Obregón, afternoons and evenings, for a complete sampling of its urban pleasures; shopaholics with an eye for edgy design won’t want to miss the whimsical boutiques that line adjacent Cerrada Colima. Deeper dives into side streets and nearby plazas turn up even more surprises when you’re ready for a walkabout.