Many Jigsaw Puzzles from pictures to be solved online. Many levels of difficulty and a lot of categories.
http://www.99puzzles.com/
http://99puzzles.com/Nature/category/
http://99puzzles.com/Architecture/category/
http://gojig.com/
http://justjigsawpuzzles.com/
http://www.hdpuzzles.com/
https://thejigsawpuzzles.com
https://yojigsaw.com
https://bestjigsawguide.com/
