...are these playhouses?
They're called Hobbit Holes! What kid wouldn't be in heaven with one of those in their yard?! We have a playhouse (pictured below) in our yard that we've had since Parker was about two. The past few summers I keep thinking it may be the last summer we keep it but she still loves it. She and our neighbor were in there for hours on the first nice afternoon this past month. Even though she's getting too tall for it she still plays in it. We'll for sure keep it for another year or two. Do your kids have backyard play houses? I definitely think they are worth the investment (and ours was pretty cheap to buy and we gave it an inexpensive makeover after a few years) as they provide hours of imaginitive play. Check out my post here on playhouses from a while back.