The Soumaya Museum, located in Nuevo Polanco in Mexico City, was designed under the direction of Romero in 2010. The museum has an area of 22,000 square meters and exhibits about 70,000 objects from different collections from the 15th century until the 20th century. The exterior facade is composed of sixteen thousand hexagonal tiles, which generate a different effect depending on the angle at which you are standing. The internal structure is composed of a ramp with 6 floors, each one with a specific theme.

The design of the museum reflects the collector's eclectic taste, as well as his desire to create a new cultural institution for the public and the city. Rising 150 feet (46 m) at the heart of a new cultural and commercial district, the building's form is clad in a skin of 16,000 hexagonal mirrored-steel elements, refering the traditional, colonial ceramic-tiled building facades in Mexico City and giving the building a distinctly different appearance depending on the weather, time of day and the viewer's vantage point.