I have hosted multiple FIFA World Cup matches, and I am known for my unique roof structure, a feature that has been likened to a 'spaceship'. I am located in a city that hosted the Summer Olympics. Which stadium am I?

1. My construction was completed in the early 2000s.
2. My city is famous for its football clubs.
3. I have a retractable roof that can be closed during bad weather.
4. My seating capacity is approximately 75,000.