Fethiye or Kas?

Both are excellent bases for swimming on the same clear coast, but the swimming is different. Fethiye's main draw is the sheltered turquoise lagoon at Oludeniz, with the open bay beside it, plus sandy Kidrak and the boat-only beach at Butterfly Valley. The town's own beach at Calis, breezy coarse sand and pebble, is the weakest of the lot.

In Kas you step off wooden decks and rock platforms straight into deep, very clear water in the middle of town, and there are only small pebble beaches nearby. For sand you have to head out, either to the cove at Kaputas below its gorge or to the long dune-backed beach at Patara.

Neither town is a food destination, and both rely on the same coastal staples: meze, grilled fish and rakı by the harbour. Fethiye's special ritual is the fish market, where you buy at the stalls and a restaurant on the square cooks it for you, though its resort strips lean towards English breakfasts and pizza. Kas has no package-menu fringe, and a few kitchens cook with herbs from the Lycian hills, but its handful of restaurant streets soon start to feel repetitive and prices follow the yachts.

Fethiye has more to see, although neither is a heritage town. It has the temple-fronted rock tombs of Telmessos above the streets, the Roman theatre by the harbour and a small museum. Just over the ridge is the deserted Greek village of Kayakoy. Together they make a satisfying day or two.

Kas has a smaller set of the same Lycian remains: a Hellenistic theatre facing the sea, tombs cut into the cliff and the Lion Tomb at the top of the shopping lane, plus the whitewashed Greek-era houses of the old quarter. That fills a morning, and the major sites are outside town.

Fethiye gives you a real choice of evenings. The lit lanes of Paspatur have cocktail bars and rooftop terraces for an easy drink, and in summer Hisaronu's strip of karaoke, loud bars and clubs keeps going into the early hours.

Kas has no clubs to speak of. An evening there means a late dinner and then a drink in the music bars behind the harbour, where divers and yachting crowds keep a few places busy past midnight in high summer. In both towns, winter evenings end early.

Both sit where mountains drop into the sea, both lie on the Lycian Way and both are within reach of the wading canyon at Saklikent, so either is excellent for the outdoors. What differs is the speciality. Fethiye is best known for the tandem paraglide from Babadag, almost 1,970m high, down to the Oludeniz lagoon, and the cliff path past Butterfly Valley and Kabak starts close by.

Kas is above all a diving town. It has walls, caves, amphorae and wrecks a short boat ride out in some of the clearest water in the Mediterranean, and sea kayaking over the drowned ruins at Kekova.

Both are good bases for ancient Lycia, and Xanthos, Letoon and Patara are within reach of either. From Fethiye the trips run west and inland, to hilltop Tlos, the tomb-filled cliff at Pinara and the river boats of Dalyan. In season, a ferry also makes a day in Rhodes and its walled medieval Old Town possible.

From Kas the trips run east and out to sea. There is the sunken city at Kekova and the castle village of Simena, the tombs of Myra and the church of Saint Nicholas at Demre, and the short crossing to Kastellorizo, a much smaller Greek island than Rhodes.

Fethiye is clearly easier with young children. The Oludeniz lagoon is shallow, sheltered and warm, many hotels around Hisaronu and Ovacik are built around pools and family rooms, and a small water park and boat trips fill out the week.

Kas is calm and welcoming, but swimming in town means ladders into deep water and the lanes are steep, so small children need trips out to Kaputas or Patara. It works better for older children who can snorkel or want to try diving.

Neither has a railway. Both centres are small enough to walk, minibuses run along the coast, and the inland ruins need a hire car or a tour. Fethiye's centre is flatter, with a waterfront path round the bay, frequent dolmus to Oludeniz and Kayakoy, water taxis to Calis and Dalaman airport about 45 minutes away by road. Kas's lanes climb steeply, and its harbour boats to Kekova and the Greek island reach places that the twisting coast road cannot.

Fethiye has more to browse, mostly in market form. The long covered weekly market by the canal sells spices, honey, cotton towels and textiles, and the lanes of Paspatur have carpets, leather, ceramics and lamps.

Kas is smaller and more boutique, with a couple of lanes shaded by bougainvillea that sell silver jewellery, linen clothes, kilims and work in a few galleries. Neither is worth a dedicated shopping trip.

Fethiye is the cheaper of the two, as long as you stay in the town itself. A family-run guesthouse, meals at the lokantas and the market, and rides round the bay by dolmus all cost little, and the rock tombs and other ancient sites charge only modest entry. Move out to the lagoon at Oludeniz or the strip at Hisaronu and you pay ordinary Mediterranean resort rates for beds, seafront dinners and sunbeds.

Kas sits at a higher level overall, as one of the more upmarket small resorts on this coast. In summer its boutique hotels, harbourside restaurants, dives and boat trips cost much what they would in southern Europe. You can still eat cheaply at simple lokantas, pide bakeries and the weekly market, ride the minibuses for little, and pay less for a pension in the back streets than for a hotel on the peninsula, but there are fewer of these options than in Fethiye town. Visiting in spring or autumn brings prices down noticeably, and in either town paragliding, diving and alcohol are what push the bill up.

Neither has a theatre season or a concert hall, so performance is not a reason to choose either. Fethiye has a modest cultural centre with occasional events, mostly in Turkish, and saz players in the meyhanes. In Kas the best you can hope for is an occasional concert in the small ancient theatre by the sea or the town's summer festival.

Fethiye has the stronger bathing tradition. A historic Ottoman hammam in Paspatur offers the full ritual of hot marble, scrubbing and foam massage, and retreats on the terraces above Kabak and Faralya run yoga weeks. If rest is the aim, stay away from Hisaronu in summer.

Kas has no historic bathhouse, only hammams in some hotels and yoga retreats in spring and autumn. Even so, the town is quiet, and its long breakfasts and sun decks over the sea suit anyone who relaxes by doing very little.