Fiddlers Ferry Power Station
As far as exposure and sharpness gets with 16 stops of stacked nd filters this is the best result I've had to date.
The histogram was pretty much perfect on this one (before I started messing with it in post-processing!) and there was little wind so no camera shake on the tripod.
6 minutes at f8 with a Nikon 16-85vr lens...I even remembered to switch off the vibration reduction on the lens :-)