Go here: http://vgmaps.com/Atlas/PC/index.htm#C and search for Crystal Caves

Here is a handy guide to show which level is which when we're talking about them https://docs.google.com/spreadsheets/d/1eUPd5BqyylpGAJdxhzdz9Mn0EIiAU-egMA99DZJqz4o/edit?usp=drivesdk