これが英会話の基礎練習！

受動態の過去形の練習をしましょう。
建てる＝　build - built - built
建てられた＝ was/were built

「この城は500年前に建てられた。」
This castle was built 500 years ago.
This castle wasn't built 500 years ago.
Was this castle built 500 years ago?
Yes, it was.
No, it was't.
When was this castle built?
It was built 500 years ago.

声を出してしっかり練習してください。