You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Warsaw

Context:
The 17th century Royal Ujazdów Castle currently houses Centre for Contemporary Art, with some permanent and temporary exhibitions, concerts, shows and creative workshops. The Centre currently realizes about 500 projects a year. Zachęta National Gallery of Art, the oldest exhibition site in Warsaw, with a tradition stretching back to the mid-19th century organises exhibitions of modern art by Polish and international artists and promotes art in many other ways. Since 2011 Warsaw Gallery Weekend is held on last weekend of September.

Question:
What castle currently houses the Centre for Contemporary Art?

Royal Ujazdów Castle