During the week a handful of craftspeople and a few scruffy pigeons are the only ones enjoying the shade from the stately trees in the city's second-oldest square. Sunday couldn't be more different: scores of stalls selling antiques, collectibles, and just plain old stuff move in to form the Feria de San Pedro Telmo (San Pedro Telmo Fair). Tango dancers take to the cobbles, as do hundreds of shoppers (mostly tourists) browsing the tango memorabilia, antique silver, brass, crystal, and Argentine curios. Note that prices are high at stalls on the square and astronomical in the shops surrounding it, and vendors are immune to bargaining. Pickpockets work as hard as stall owners on Sundays, so keep a firm hold on bags and purses or—wiser still—leave them at home. More affordable offerings—mostly handicrafts and local artists' work—are on the ever-growing web of stalls along nearby streets like Defensa. Be on the lookout for antique glass soda siphons that once adorned every bar top in Buenos Aires. Classic colors are green and turquoise. Be sure to look up as you wander Plaza Dorrego, as the surrounding architecture provides an overview of the influences—Spanish colonial, French classical, and ornate Italian masonry—that shaped the city in the 19th and 20th centuries.