Link Directory: Letterboxing Portals
- Atlas Quest: Atlas Quest, dedicated to providing tools and information for letterboxers from around the world, is one of the largest and fastest growing letterboxing sites on the Internet.
- Letterboxing Basement: Where old boxes go to die. Just kidding. But it does have old clues often not found anywhere else from the days before you could list your own boxes on LbNA.
- Letterboxing Germany: Has information and clues for letterboxing in Germany and Continental Europe
- Letterboxing North America: The "main" letterboxing website that started it all
- Letterboxing on Horseback: The official website of the Letterboxing on Horseback club
- Letterboxing Scotland: Clues for letterboxing in Scotland
- Letterboxing.info: Articles about letterboxing and an extensive directory of other letterboxing resources on the web
- New Zealand Letterboxing: The website for information about letterboxing in New Zealand, maintained by Team Psychokiwi
- Urban Letterboxing: Letterboxes in urban locations—especially in Europe