When people talk about the tallest man-made structure, most people think about buildings as Burj Khalifa, Tokyo Sky Tree, CN Tower etc. However, offshore structures are far even taller than the tallest building.
You will be amazed if you see the info graphic below.
Credit: http://theogm.com
Perdio Regional Host = 2,438 m (7,999 ft)
Ursa Platform Tower = 1,306 m ( 4,285 ft)
The Petronius Compliant Tower = 640 m ( 2,100 ft)
Baldplate Compliant = 579.7 m ( 1,902 ft)
Bullwinkle Platform = 529.1 m ( 1,736 ft)
Troll A Platform = 472 m( ft)