Casa Mila, also known as La Pedrera, is a modernist building located in the Eixample district of Barcelona, Spain. It was designed by the Catalan architect Antoni Gaudí and built between 1906 and 1912 for the Milà family. The building is considered one of Gaudí's most innovative works and is a UNESCO World Heritage Site.

Casa Mila features a curved stone facade that undulates like a wave and is punctuated by wrought-iron balconies with organic shapes. The roof is also remarkable, with its unusual shapes and the sculptures that adorn it. The interior of the building features an atrium that is illuminated by natural light and serves as a central space for the various apartments. The apartments are decorated with frescoes, tiles, and other ornamental details.

Casa Mila was controversial when it was first built due to its unconventional design, and was often derided as "La Pedrera," or "The Quarry." The building has since become a beloved icon of Barcelona and is widely regarded as a masterpiece of modernist architecture. Today, it serves as a museum and cultural center, offering visitors a chance to learn about the life and work of Antoni Gaudí, as well as to admire the building's unique features and stunning views of the city.