If you are interested in watching some heavy construction activity pretty much 24/7, there are live webcams of the new Tottenham Hotspur Stadium in North London.
Some big cranes in action, as well as plenty of other stuff.
This is a football (soccer) stadium, but it has also been designed to host NFL games and it will have a fully retractable pitch.
Tottenham Hotspur webcams
http://www.CranesEtc.co.ukhttp://www.Twitter.com/CranesEtchttp://www.YouTube.com/CranesEtcTVCranes Etc on Facebook