Renovating the backyard

So we've begun the process of redoing the backyard.  We were going to update our deck and add some additional decking, but of course it did not work out that way.  So now it has turned into a major demolition and rebuild project.

Here's the location of the old deck:

This is the central portion, where the hot tub used to be:

Here's the area for our "retreat" - note the trench on the right (for drainage, because you don't want the retreat to be underwater):

And, just for fun, this is the way you saw out portions of your existing concrete patio:

It looks worse than it is, and it will be really nice when it's done.