The Green Tour is:
- The underground city of Kaymakli or Derinkuyu
- Selime cave monastery
- Ihlara Valley (the walking part of the tour is 4 km).
If you want to see everything, then by all means take the tour. However, the cave monastery is the standard views throughout Cappadocia, the Ihlara Valley is just nature along the river. That leaves the underground city, which you can visit on your own - will come out 3 times cheaper. It's up to you)