The I-tunnel is a tunnel linked with the N-tunnel. It is 7 levels long. Branching out are the C-Tunnel (I-1) and H-Tunnel (I-7). Like the N-Tunnel, it uses conveyor tiles, but there are also sideways conveyor tiles, different to the N-Tunnel. I-5 is insanely hard (as hard as Plan A, part 16) and is in the poll.