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:
Westminster_Abbey

Context:
The chapter house has an original mid-13th-century tiled pavement. A door within the vestibule dates from around 1050 and is believed to be the oldest in England.[citation needed] The exterior includes flying buttresses added in the 14th century and a leaded tent-lantern roof on an iron frame designed by Scott. The Chapter house was originally used in the 13th century by Benedictine monks for daily meetings. It later became a meeting place of the King's Great Council and the Commons, predecessors of Parliament.

Question:
A door in the vestible dates back to when?

1050