It's impossible to visit Kabak without visiting Fethiye first, so here are some tips to make your time there more enjoyable. Note that the nearest airport is in Dalaman (about an hour away by minibus) and that the otogar (bus station) is a couple of kilometers away from the center, although if you are staying in Fethiye you can catch a dolmus into town. Most long distance bus companies also provide a servis (feeder) minibus which will take you to your destination on presentation of your original bus ticket.
Fethiye is a reasonably pleasant small port that is primarily a resort center for the beaches in the surrounding region. The only historical sights of note in the town itself is the remains of the Lycian city of Telmessos, which includes an amphitheater and several rock tombs. There's an entrance fee to the Tomb of Amyntas, but as you can more or less see everything from the road it's not worth paying the extra fee to visit. Fethiye is also the point of departure for a pair of popular day boat trips, one goes to Faralya and the Butterly Valley while the other visits 12 islands in Fethiye Bay and hence is known as the "12 Islands Tour." Each should cost no more than 25 TL (if you're paying more it means someone is taking a commission!) and includes lunch and several opportunities to go swimming in the sea. However, you should check before taking one whether it includes loud music as well! (Drinks are extra).
Kaya Koyu and Oludeniz:
The abandoned village of Kaya Koyu is either long walk (along the Lycian Way) or a short dolmus ride from Fethiye (the dolmuses run approximately on the half hour in summer). During the Ottoman Empire, Kaya Koyu was the Ottoman Greek village of Levissi. After the Turkish War of Independence, Turkey expelled its "Greek" inhabitants while Greece expelled its "Turkish" inhabitants in the so-called population exchange, in which the only criterion was religion, with the result that many people found themselves in countries whose language they did not speak, not to mention significant economic hardship. Since there were far more Greeks in Turkey than vice versa, villages like this one were abandoned.
Officially, it costs 8 TL to enter, but if you follow the Lycian Way as you enter the village you won't have to pay - this is the best way to enter anyway as it leads to a lovely (and for the most part clearly marked) path over a mountain that takes you to the white sound lagoon of Oludeniz in an hour and a half with numerous beautiful views on the way. Oludeniz is one of Turkey's prettiest beaches and unfortunately also one of the most crowded and as a result the water can be disconcertingly murky. It's also one of the best places in Turkey to go paragliding, although as I didn't do so personally I can't vouch for this. Dolmuses run back to Fethiye from the beach, through the concrete resort dormitories of Hisaronu and Ovacik, whenever they're full.
The most interesting ruins in the general vicinity of Fethiye are the Lycian, Greek, and Roman ruins at Xanthos, near the village of Kinik. To get there, you can take a dolmus to Kinik or sign up for one of the tours that visits them and the cool waters of the Saklikent Gorge (itself a pleasant experience, particularly on a hot summer day). The Xanthians were one of the members of the Lycian Confederation and are perhaps best known for committing suicide and setting their city on fire twice rather than surrender to enemies. Given this tragic history, it's perhaps appropriate that Xanthos has a marvelous collection of Lycian Rock tombs. It also offers a nice viewpoint over the appropriately windy Meander River (from which the English word comes), known as the Menderes in Turkish. Admission is 3 TL.