Amazon has triggered a $5 billion bidding war - here are 7 of the most ambitious site proposals for its new headquarters

In early September, Amazon announced that it plans to build a $5 billion campus, dubbed HQ2, and bring 50,000 jobs to an undetermined North American location.

At least 50 cities in the United States and Canada are expected to submit proposals for sites they believe would be the best fit for the e-commerce giant.

For some cities, the offer sounds too good to pass up. Many are offering generous tax incentives and opportunities to develop huge swaths of land to the company.

Here are some of the most ambitious sites that cities are proposing for HQ2: