"To those who do not know...it is difficult to get across a real feeling as to the beauty, the deepest beauty, of nature ... If you want to learn about nature, to appreciate nature, it is necessary to understand the language that she speaks in."
-- "The Character of Physical Law", by Richard P Feynmann
Puzzlebox is more than just the world. Puzzlebox is more than just the terrain. Puzzlebox is more than just home. Puzzlebox is a mind, a machine, and quite possibly somebody's idea of a joke. Nobody ever tries to talk about how big Puzzlebox is, unless they're being ironic. It folds in on itself in such arcane patterns, trying to measure it would be an exercise in neurosis. It's big, that's all, big enough that nothing outside it really matters. And it's still growing.
Puzzlebox has been growing since before the oldest written record -- probably since before the oldest biological life. There is no record of its builders, if it had any. It seems to build itself, and it may have created itself. It's not unusual for Puzzlebox to extend another 50,000 km into the void in a single day.
Twin claims Puzzlebox is a {she}.
Also, "Puzzlebox" is the name of the free-form textual RPG this is all about. There's lots more detail in the Newbie Guide.