One of my favorite Heinlein novels is Tunnel in the Sky. It’s one of his juveniles and features a group of young people who are training to be interstellar scouts. They are dropped on another planet for a survival test…and stranded there. In many ways, this book is in conversation with Lord of the Flies. It’s also about scouting.

And it features the concept of a stargate…a portal from planet to planet that can be used to transport people instead of flying around in ships. The term stargate is also sometimes used to refer to a static portal to throw ships into hyperspace.

And, of course, it’s a media franchise. Stargate SG-1 was extremely popular and still holds up.

Unfortunately, this means a search for “fiction containing stargates” will get you pages upon pages about the franchise.

And “interstellar portals” doesn’t help either!