The formidable compound now known as ‘The Citadel’ started off as a tobacco factory in the late 18th century, though it’s best known as the scene of the Decena Trágica (Tragic Ten Days), the coup that brought down the Madero government in 1913. Today it's home to the Biblioteca de México José Vasconcelos, which has holdings of more than 500,000 volumes and an extensive map collection. The central halls of the recently renovated building are given over to art exhibits.

Centro de la Imagen, the city’s photography museum, is at the Calle Balderas entrance. This innovatively designed space stages compelling exhibitions, often focusing on documentary views of Mexican life.

Across the plaza, inside the Centro de Artesanías La Ciudadela, vendors offer a wide array of crafts from around Mexico, including black pottery from Oaxaca, guitars from Michoacán and silver jewelry from Taxco. Prices are generally fair, even before you bargain.