question: What was the purpose of the castle
answer: The heavily fortified castle Vredenburg was built to house a large garrison whose main task was to maintain control over the city
turker_answer: The heavily fortified castle Vredenburg was built to house a large garrison whose main task was to maintain control over the city .
rule-based: The purpose of the castle was the heavily fortified castle Vredenburg was built to house a large garrison whose main task was to maintain control over the city