It's possible to make a day-trip excursion by train from Ephesus to Pamukkale and return in the same day, or leave your heavy luggage with the Emanetçi (Left Luggage/Checked Baggage) at the Denizli Otogar, visit Pamukkale, then continue on a night bus to Cappadocia, the Mediterranean coast, or Istanbul, or fly to Istanbul.
You may even be able to visit Laodicea on the same trip.
Unfortunately, it's difficult to include a visit to Aphrodisias on this day-trip—not enough time. For that, an overnight at Pamukkale is best.
Besides İzmir-Selçuk-Denizli trains, there are a few buses daily between Selçuk (Ephesus) and Denizli (for Pamukkale), but note that the last bus and train of the day to Selçuk depart in late afternoon. There are none in the evening, so if you miss it, you'll have to travel via İzmir, taking more time.
This itinerary includes 30 minutes to one or 1-1/2 hours of walking, some of it over rough, irregular surfaces, perhaps in hot sun. If you have mobility challenges, the itinerary may not work for you.
Times in the itinerary below will vary by how long you want to spend at each point and activity, but the itinerary will give you an idea of what you must do to make the excursion work.
Selçuk - Pamukkale in 1 Day
09:00 am: Train Selçuk - Denizli
Depart Selçuk (Ephesus) by train for Denizli, arriving about 12 noon. If you take a seat on the left side of the train, you can see the white swath of Pamukkale on the hillside as you approach Denizli.
There may be a bus departing for Denizli and/or Pamukkale earlier than the train. Check at the Selçuk Otogar a day before you plan to travel.
12:30 pm: Minibus Denizli - North Entrance
Walk out the front door of the Denizli Gar, turn left, climb the stairs, and look a bit to the left. Across the boulevard you will see a modern cylindrical glass building, and to the right of it the sleek, modern Denizli Otogar (bus terminal).
Walk left, cross the boulevard at the crosswalk, enter the bus terminal and take an escalator/moving stairway down to the lower level, the one for minibuses to nearby towns.
Find Peron 76 (Gate 76), from which minibuses depart every 15 or 20 minutes for Laodicea, Pamukkale and Karahayıt. Take a seat in the minibus.
Fares should be posted in the minibus. You can pay the driver at the beginning or end of the ride, or while traveling. Say this to the driver: Örenyeri Kuzey Giriş (ur-REHN-yeh-ree koo-ZEY gee-reesh, "Archeological Site North Entrance"). In 20 minutes or so the minibus will go through the center of Pamukkale Town, then up a winding road toward Karahayıt. The driver should drop you at the North Entrance about 30 minutes after departing Denizli, before coming to Karahayıt.
13:00 (1 pm): North Entrance to Ancient Pool
From the North Entrance you can walk in 20 to 30 minutes over the ancient rough-stone road through the vast North Necropolis to the Antique Pool and the Archeological Museum at the center of the Pamukkale/Hierapolis ruins.
If you'd rather not walk, a Servis Arabası (Shuttle Van) waits inside the North Entrance to shuttle you there for TL2 per person.
13:30 (1:30 pm): Hierapolis Ruins & Archeological Museum
The time you spend sightseeing among the ruins depends on your interest. You can see the high points—the theater, the Antique Pool, the Archeological Museum, other ruins of Hierapolis, and the panoramic views over the travertines and the valley below—in as little as one hour. If your visit goes quickly, you may be able to include a visit to Laodicea in your day excursion (see below).
15:30 (3:30 pm): Walk Travertines to Pamukkale Town
Leave the Antique Pool and Museum area no later than this time. The walk, shoes off, through the travertine pools and the running water, to the Pamukkale Town exit of the archeological site takes about 30 minutes.
There is no standard path. You make your way through the pools. At the bottom, walk to the center of Pamukkale Town and wait on the lower side of the mosque to catch the minibus back to Denizli.
If you prefer not to walk down to Pamukkale Town, you can ride the Servis Arabası (Shuttle Van) from the Ancient Pool and Museum back to the North Entrance, and wait on the road for a minibus coming from Karahayıt to take you back to Denizli.
16:15 (4:15 pm): Minibus to Denizli
Play it safe and take a minibus that departs Pamukkale Town no later than this time. It should get you to Denizli Otogar in about 30 minutes, which gives you time to cross the boulevard to the train station and get settled in your seat before the train departs.
17:15 (5:15 pm): Train Denizli - Selçuk
The train arrives at Selçuk around 20:44 (8:44 pm).
If all goes quickly and you can get to the center of Pamukkale Town and be ready to board a minibus by 14:45 (2:45 pm), you can include a short visit to the Laodicea archeological site on your day excursion. Built of smooth blue-white marble and thus quite different from the rough, tawny marine limestone of Hierapolis.
15:00 (3 pm): Minibus to Laodicea
Board the minibus and say this to the driver: Laodikya inecek (lah-oh-DEEK-yah ee-neh-jehk, "Get out at Laodicea"). In about 10 minutes the driver will drop you near Laodicea.
15:15 (3:15 pm): Laodicea
The minibus will drop you by the Denizli Veterinerlik Hizmetleri building. Walk west on Ören Caddesi for 12 minutes straight to the entrance to the archeological site, then, after buying your ticket, another 10 minutes uphill to the ruins. More...
16:00 (4 pm): Walk to the Main Road
Start your walk back along Ören Caddesi to the main road no later than this time. The walk is a bit faster downhill.
16:20 (4:20 pm): Minibus to Denizli
Be back on the main road and ready to catch a minibus to Denizli Otogar by this time to assure your arrival in Denizli in time to catch your train. Signal to the minibus driver so he knows to stop for you.
If You Miss Your Train/Bus
If you miss the last train or bus of the day to Selçuk (Ephesus), don't worry. You won't have to spend the night in Denizli without your toothbrush. Buses to İzmir depart about every half hour all day and into the evening. Take one, go to İzmir, then take a minibus from İzmir Otogar back to Selçuk. The trip will be longer (perhaps 5+ hours), and you'll arrive back at your Selçuk hotel later, but you should be able to get there.
When you arrive in Denizli, check at the Denizli Otogar for departure times and seats onward to your destination. Buy your ticket, deposit your heavy luggage at the Emanetçi (Left Luggage/Baggage Check) on the lower (minibus) level of the bus terminal, and enjoy your day at Pamukkale.
Here's how to go from Denizli and Pamukkale to Cappadocia.
—by Tom Brosnahan