Over the last 25 years, the number of new cities being built around the world has more than doubled compared to the previous 50 years. While some have been branded vanity projects, others are vital investments to help weather the impacts of climate change or relieve congestion in crowded capital cities.

No matter the motivation, vast sums of money are being spent on ambitious future developments, often with disappointing results. Read on to discover 13 cities of the future that are currently under construction, ranked by their staggering price tags.

All dollar amounts in US dollars.