Two mile thick ice
Have you ever read the statement that the ice sheet over much of North American during the last ice age was over 2 mile thick?
Well here is a photo from 2 miles above the land.
For the record, the North American ice sheet at the peak of the last Ice Age was 2 miles thick only over middle of the continent in the area of Hudson Bay: http://www.clim-past.net/9/2365/2013/cp-9-2365-2013.pdf.