Rope bridges are wonderful things and are perhaps the ultimate way to access a treehouse (well, besides a zip line from one's bedroom). Our typical rope bridges have large diameter natural fiber ropes for handrails with smaller diameter rope interwoven. The main support comes from underneath the treads rather than above as in a suspension bridge. The loads on the bridge supports can be very large so we must use very high strength materials. Rope bridges are costly accessories as they must be over-engineered to never fail while at the same time maintaining a lightness of design.