Why do my parents have a helicopter landing pad? Not because they are James Bond-types. My dad has spinocerebellar ataxia, which affects his balance, among other things, so he does fall over and need emergency care with some frequency. My folks live out in the country, at the end of a steep, curvy driveway that gets icy, so they have the potential need for emergency evacuation by helicopter. A helicopter pad needs a big flat space, with even flatter bits in the middle for the helicopter to land on. Hence, the labyrinth.
The picture below is a satellite view of my parents’ modern house. To the right is the labyrinth. Wending around the house is the driveway on which my car was hit, causing nearly $6k in damage early this fall. Besides being curvy, it also has some steep shady parts, so it is easy to get iced in.  (Or out. I got stuck on the driveway coming home one night last winter.)
I lifted many of these photos and the following text from my dad’s Christmas letter almost verbatim, although rearranged and with just a few more words for context.
This was a low spot in the center of the labyrinth. There is a hardpan down about 45 centimeters. It was often wet and mushy, dried slowly, and things died of “wet feet.â€
Don dug it down to hardpan and then dug dry wells through the hardpan in a couple of places to let the water through.
We started with about a tonne (1000 kg.) of flat rocks. They have now all been used.
We also had 7,000 liters of gravel. [The gravel has not all been used.]
 [In process.]
 [Almost done.]
Then we filled the dry wells and the excavation with gravel up to about fifteen centimeters from the surface followed by about ten centimeters of pulverized limestone. Then Don leveled things, cut the rock to size, and placed it.
 This is essentially the finished product and I think it looks very good. Don says that we will need to work in some more pulverized limestone as that in the cracks settle.
