Thanks Anatoly this is Bonneville Dam completed in the late 1930s as part of the "New Deal" to overcome the Great Depression that saw over 30% of Americans out of work. Over 80 years later it is still an important source of electrical energy in the Northwestern US. Also thanks for the reminder to use live-view with this lens - the focus is very very sensitive and the only way to ensure accuracy is to enlarge the intended subject area in live view and set the focus - which of course means using a tripod