Getting the visible rect of an UIScrollView's content

Question

How can I go about finding out the rect (CGRect) of the content of a displayed view that is actually visible on screen.

myScrollView.bounds

Answer 1

Swift 4.0:

My answer adapts Trenskow's answer to Swift 4.0:

let visible = scrollView.convert(scrollView.bounds, to: subView)

where scrollView is the view of the scroll, and subView is the view inside scrollView which is zoomable and contains all the contents inside the scroll.