Findings:

• Blue John
• castle crawler (user)
• how to catch nite crawlers
• Regex Crawler
• crawler dozer
• web crawler
• catching night crawlers
• TIE Crawler
• crawler
• Wailing Caverns
• Cumberland Caverns
• Stump Hole Cavern
• The Cavern Under the Sea
• Kartchner Caverns State Park
• Luray Caverns
• Pitfall II: The Lost Caverns
• Florida Caverns State Park
• Secret Caverns
• Howe Caverns
• Caverned
• Cavern
• Carlsbad Caverns National Park
• Caverns of Zeux

If you Log in you could create a "Cavern Crawler" node. If you don't already have an account, you can register here.