A hot air balloon flight
The open air museum
The underground city

However, if you are into hiking, one of the valleys might be better for you.

You could probably do all of these if you hire a driver for the day. The balloon flight is so early, you get back to your hotel in time for a late breakfast. Have a driver pick you up and go to the open air museum, then to the underground city and stop at one of the valleys at sunset to walk an hour or so.

Thank you. I haven't had much time to research all this so I don't know locations and distances. If we wanted to hire a driver from the Kayseri airport and back again, which sights would you recommend that we could do in one day if we would like:
Open Air Museum
One of the Valleys with the Fairy Chimneys
An Underground City
Cave houses or churches
Perhaps a nice little village
Hiking would be nice if possible.

OK, I am sorry. I mis-read. I thought you were staying there and had a full day on the ground. We took a late evening flight in and stayed three nights. I did so much research, now don't remember which airport we ended up using, but it was 30/40 minutes from any sights and our hotel.

Assume you are coming from Istanbul. Though it is beautiful and I can see why you would want to do it, I would probably not even consider a day trip to Caqppadocia. I hope someone else can give you better advice for what you want to do.

Hi Abbyo.. i recently returned from Turkey and cannot highly enough recommend http://www.propertravel.com for a customized day in Cappadocia. You can contact them directly and tell them your interests, and they will put together a tour around that. They can pick you up at the airport and go from there.. Our guide was Ismael and he picked us up at our hotel in a really nice car with driver. We talked a few minutes about some specifics (my claustrophobia, my friend's photography requirements, our desire to see churches and do some hiking) and then had a great day. He took us to a smaller underground city where there were less people so i wouldnt get anxiety, and we were at the most picturesque places at sunset. I hope you enjoy your time there! its a beautiful beautiful place.

must see's for me were the cave churches, underground city, hiking around the fairy chimneys.. favorite eateries. We actually didnt do the Hot Air Balloons, or Open Air Museum.. more for next trip.

We had a great tour with cappadociatours.com. Ours was a multi-day tour but I would imagine they could set up single day tours as well. Our guide, Fathi, was terrific -- try to ask for him, if possible.