<human>:  What are the top three things to see in Barcelona?
<bot>: 1) The Sagrada Familia: Barcelona's most famous and iconic landmark, this elaborate Roman Catholic basilica was designed by famous Catalan architect Antoni Gaudi and has been under construction since 1882. 2) Park Güell: This large park designed by renowned architect Antoni Gaudi features colorful mosaics, stunning architecture, and breathtaking views of Barcelona. 3) La Rambla: The famous pedestrian street of Barcelona is lined with shops, cafes, and street performances, making it a must-see for visitors.