I bought and put one together in our backyard, during my second maternity leave.  Our oldest daughter at the time was three, and we were having twins.  Even though there was a park just across the street, my wife thought it would be a lot easier to just walk into the backyard.  Trying to to coax a three year old, and push twin babies in a stroll would have been a handful.  So, one fathers day, so many years ago, I put one up in the backyard.  A few years later, I even added an addition to it comprised of climbing rungs, and another ladder.  It’s still there to this day, and our oldest is now 16.  I think it may be just about time to take it down.