Popular Mechanics presents a quick description of the world's 25 most impressive megaprojects; the biggest and boldest projects on the planet, including:
- Al Maktoum International Airport, Dubai
- Marmaray Tunnel, Turkey
- London Crossrail, London
- Panama Canal Expansion, Panama
- Three Gorges Dam, China
Update 07/09/15: top 10 most impressive civil engineering projects of all time according to the Norwich University's Civil Engineering Department (completion dates from 2011 until 2504 B.C.)