The circular can be started in Göreme or Uçhisar.
For Göreme, don't hesitate to stray from the town centre where parking can be difficult to find.
The circular route can be done in either direction, but I find that the Pigeon Valley is a gentle way to start.
The terrain is varied and some sections can be a little difficult. Nevertheless, the route is accessible, even for children aged 8-10.