1. La Casa Batlló was designed by Antoni Gaudí, a Catalan architect known for his unique, organic style that incorporated elements of nature into his buildings.
2. The building was commissioned by textile industrialist Josep Batlló and was constructed between 1904 and 1906.
3. The facade of La Casa Batlló is adorned with intricate mosaics made from broken ceramic tiles, known as "trencadis", and features a number of sculptural elements such as the dragon-shaped roof and the pillars that resemble bones.
4. Inside, the building has a number of unusual features such as a roof terrace with undulating walls, a central atrium with a skylight in the shape of a star, and a hall of mirrors with walls made of stained-glass.
5. La Casa Batlló is now a museum and cultural center that is open to the public, and it is considered one of the most important works of Gaudí's career. It was designated a UNESCO World Heritage Site in 2005.
To get more information about the entrance tickets, you can visit https://www.casabatllo.es/