This building is considered one of the purest examples of Neoclassical architecture in Mexico, it is located in front of Plaza de la Paz. 

This pink quarry building is the work of Architect Francisco Eduardo Tresguerras and belonged to Diego Rul, a Malagan who held the title of Count and was married to Doña Ignacia Obregón, daughter of Don Antonio de Obregón, the discoverer of the La Valenciana mine, which became the most important mine in the country.

It has two entrances, one through Plaza Mayor and another on the second floor level on Positos Street.

The house was completed between 1800 and 1802 and is a two-story building.

This house is surrounded by several legends, such as the Countess Doña Ignacia refusing to leave through the front door to avoid ridicule due to her husband's affairs. The alley that leads to the other door is even called Callejón de la Condesa (Countess Alley).

Actualmente ha sido convertida en el Museo del Conde Rul y cuenta con 10 salas de exhibición, cinco en la parte baja y otras cinco en la parte alta. En ellas se presenta la obra de destacados artistas como: Diego Rivera, José Chávez Morado, Luis Nishizawa Flores, Feliciano Peñoa, Olga Costa, Luis García Guerrero, el maestro Jesús Gallardo y Javier Hernández “Capelo”,  así como algunos trabajos en óleo y tintas del artista mexiquense Luis Nishizawa Flores.

Additionally, visitors can contemplate works by 19th-century painters, including José María Velasco, better known as Dr. Atl.