It was a miniseries based in the United States:
The show’s premise inexplicably suggested the framework of society here on earth. The characters were faced with never-ending riddles, which left me piqued complete.
If you haven’t seen it, all 118 episodes are worth watching. It may take you a year, more or less to finish, but I wouldn’t resist. However, if you feel that’s too taxing, then at least try the first few episodes of the final season.