Tazz, As usual, I'm just getting caught up on the postings...my apologies for missing this one.

Tunnels are easy. I went to Home Depot or Lowe's and bought a concrete form for mail box or deck footings and gave that to the buns. They offer several different diameters. My guys love it, except it tends to roll when they're in there. So I put it between a wall and a brick so it would be more stable. Busy Bunny sells a triangular tunnel and Bunny Bytes sells a great tunnel made of willow branches. You could probably take an empty cardboard box and cut off the narrow ends, turn it upside down and that could be a tunnel too.