Guess the City

Andy and I got away for a long weekend leaving Dan and Becky with Martin and Margaret and visited a very cool US city. Can yuo guess which one from the following clues

Your starter for 10 (for our UK readers) is on architecture and is a picture round
The architectural style of this building is named after the city in which it is found, what is the style of architecture?


For 5 more points another building from the same city, this is the second biggest building (by volume in the world), what is the biggest building by volume in the world(not in this city)?
5 more points for this question. This building was built in the Neo-Gothic style to show the world that the city was up to holding which prestigious world event?

The next picture shows a famous landmark building from the same city, what was unusual about the architects who designed the building?

If you haven't already guessed the city by now here are some more iconic buildings to give you a clue.