Casa de los Lagartos (Lizards House)

Casa de los Lagartos, located at number 1 on Calle Mejía Lequerica is one of the historic structures in the center of Madrid. On the outside of the building, you can spot a number of carved creatures—they're technically salamanders, not lizards, but it's too late to change the name of such an old building now. 

Spanish architect Benito González del Valle created the structure, which includes five floors of apartments, with three art studios at the top. Commercial spaces are located on the ground floor. This building was constructed between 1910 and 1911 in the Rationalist style, which is distinguished by the simplicity of architectural and decorative lines, and has narrow lateral facades.

The façade has several distinctive features, including the absence of balconies, which were common in Madrid architecture in the late 18th and early 19th centuries.

The building does not have a patio (which was rather unique at the time), the apartments have a long hallway connecting every room, and all of the rooms open to the outside for air and light. This results in the building having a huge number of windows, which was made possible by the building's metal frame. This made it one of the first residential structures to adopt this construction approach, as it was previously only used for luxury and industrial architecture.

Last but not least, it should be noted that it is one of the few Viennese-influenced structures in Madrid, notably a Viennese Secessionist structure from the Wagner school, whose decorative components are distinguished by their geometric simplicity and symmetry.