The green valley makes a nice contrast to the surronding planes and it is a perfect place for a nice walk. You can make it a full day and walk all the way between Selime Monastery to Ihlara village, while you take your time to have a look in all the chuches and stop for lunch at a restaurant by the river.
If you, like me, visit on a daytour from Göreme you will probably make a shorter walk from Ihlara village to Belisirma and only visit one or two churches.
Ihlara Valley is a 10 km long gorge, southeast of Aksaray. The valley is full of rock cut churches, but only a dozen of them are open to the public. Several of them have well preserved paintings. It is a green gorge with a stream, Melendiz Suyu, running along it. It is a nice place for trekking.
Visit Monks Valley (Pasabag) which contains imposing fairy chimneys, many of which have 3 or 4 caps. Hermitages were carved into these chimneys and used by the monks. St Simeon the Sytlite, founder of an order of “Pillar Saints” lived in isolation in this valley.
There are day tours from Goreme (and probably some of the other nearby Cappadocian villages).
Let the owner of the pottery cut off a small piece of your hair to include in his 1 million pieces Hair Museum