Casa Siza is the rare Álvaro Siza commission you can actually rent: a clean-lined cubic townhouse in Mexico City’s Santa María la Ribera, designed by the Portuguese Pritzker laureate, with a converted garage door at the ground floor that swings open and turns the living-level gallery into a sidewalk vitrine. Lucia Corredor (AD-100) handled interiors; the contemporary collection on display includes Bosco Sodi, Izumi Kato, and Mario García Torres. The neighborhood — central, art-nouveau, walkable — does the rest.