Linked are a few image files to get started. All images are copyright and trademark their owners and are shown here for noncommerical use.
Images are located from various internet sources such as http://www.seven-wonders.co.uk and http://www.deviantart.com/
500+ Images saved to a 92 MB rar file from Darkest Dungeon:
400+ Images saved to a 18 MB rar file for Spycraft or similar modern adventures:
100+ Images saved to a 30 MB rar file for Warhammer 40K:
500+ Images saved to a 30 MB rar file for Star Wars:
70+ Images saved to a 12 MB rar file for Curse of Strahd / Ravenloft: