Hawkwind -Warrior on the Edge of Time ... although the front is ΒΌ of the image (more or less). That ravine is so deep it needed a bit more cover!
I owned ELO 2 for about 40 years before I realised what the cover depicted! It wasn't that long ago that I got the 'joke' in the band's name either to be fair.
The Moody Blues were good at this To Our Children's Children's Children A Question of Balance Every Good Boy Deserves Favour Seventh Sojourn Long Distance Voyager
And the Moodies continued the tradition in their side projects/solo albums Justin Hayward and John Lodge - Blue Jays Ray Thomas - From Might Oaks Graeme Edge Band - Kick Off Your Muddy Boots John Lodge - Natural Avenue
A different twist: for Steve Miller Band "Children of the Future" only half of the title was on the front. Some people actually thought the record was called "The Future."