In our questions for a plumber, one of the questions is, "Do you know where the cleanout for your main house drain is?"
A "cleanout" is a convenient place for a plumber to get access to the drain to "clean out" a clog without having to resort to digging up your yard to fix the problem.
Recently, I was called out by a customer with a clog. There was no clean out, so the only way to get access to it was to dig up his yard and break into the drain pipe. Rather than just replace the section of pipe with another, I went ahead and installed a cleanout so that labor would never have to be done again.
I snapped these pictures:
Here is the pipe as I found it -- with holes knocked in it by another plumber on a previous clog-hunt.
Here is the installation I did. It has the proper connections on each end with a cleanout extending above the turf.
And then here is the finished job, with the cleanout poking up next to the house.