Three days is enough to see the essentials of Marmaris if you choose well: one day in town, one on the water and one on the best day trip. The plan below is a template; swap days to suit the weather and your energy, and keep in mind that boat trips run mainly from April to October.
Day one: old town, castle and marina
Start with the guided walk through the old quarter and up to Marmaris Castle, where Suleiman the Magnificent's fleet gathered in 1522. The lanes are cobbled and steep, so go in the morning. Visit the small museum, then wander down through the bazaar, where pine honey, olive oil, spices, leather and textiles are sold, and where bargaining is normal. Have lunch near the marina, then spend the afternoon on the beach or by the hotel pool. In the evening, a Turkish bath is a restful way to end a first day, and dinner on the marina front is the classic choice. If you prefer nightlife, the bar street is a short walk away.
Day two: a day on the water
Choose a boat that suits your group. The all-inclusive bay cruise is the easy default, with swim stops, lunch and drinks. Families with young children will enjoy the pirate cruise or the calmer glass-bottom boat. If you want a bigger journey, take the Cleopatra Island and Gökova trip, which crosses the bay to Sedir Island and its ruins. Bring water shoes, sun cream and a hat. Plan an easy evening after a day in the sun: a quiet dinner and an early night.
Day three: Dalyan
The best day trip from Marmaris. After a morning drive of around an hour and a half you board a boat on the Dalyan river, glide past the Lycian rock tombs, climb through the ruins of Kaunos and take a mud bath and a swim at the beach where loggerhead turtles nest. It is a long day, so go with a tour that includes transfers and lunch, wear shoes you can walk in, and bring swimwear and a towel. Return in the early evening and eat close to your hotel.
If you have a fourth day
Add a jeep or quad safari for a splash of adventure, a day on the Datça peninsula for villages and lunch, or a slow beach day. Active travellers can swap the safari for Dalaman River rafting.
With children
Swap the castle walk for a morning at the water park, keep the pirate cruise on day two and consider Dalyan only if your children cope with a long day on the road. A jeep safari with a waterfall swim and a water fight is a favourite from about six years old.
As a couple
Choose a smaller gulet or a private boat on day two, take the Akyaka day for a riverside trout lunch in place of Dalyan if you prefer a gentler pace, and book a hamam for two.
In wet or windy weather
Boat trips can be cancelled or changed, so keep a land plan in reserve: the castle walk, the museum, a hamam, a village tour with lunch, or the Datça peninsula. The water park and boats are summer activities; outside the warm months, the village tour and the hamam carry the schedule.
Where to base yourself
For a first three days, the town centre or İçmeler is best, because boats, tours and restaurants are close. Marsyas Hotel is a central budget option, and Marti Resort Hotel is a beach resort in İçmeler.
Practical tips
Book the boat day and Dalyan a few days ahead in July and August. Carry cash for small fees, dress modestly for villages and mosques, and keep the evening before the long Dalyan day relaxed.
A note on pacing
The days are deliberately varied: a cultural morning, a day on the water and a long excursion. Do not schedule the Dalyan day immediately after a late night out, and consider the boat day or the old-town day as a flexible slot you can swap depending on the weather forecast. If you only have two days, combine the old town in the morning with a half-day boat trip, and save Dalyan for next time.