I want to know the answer to the following question:
Where do people dress in masks and costume?
All the background I'm provided with is that "In Catalonia people dress in masks and costume (often in themed groups) and organize a week-long series of parties, pranks, outlandish activities such as bed races, street dramas satirizing public figures and raucous processions to welcome the arrival of Sa Majestat el Rei Carnestoltes (His Majesty King Carnival), known by various titles, including el Rei dels poca-soltes (King of the Crackpots), Princep etern de Cornudella". Is that enough to answer the question?
Answer: yes