Trains to Izmir from Istanbul take a good 10 to 12 hours and you must first take a four-hour boat ride across the Sea of Marmara then connect with a train at Bandirma. Opt for the morning departure rather than the night one if you want to enjoy the scenery of the cruise and the ride ride along the northern Aegean coast. Contact Turkish Maritime Lines in Istanbul for schedules and fares.
You can take the train from Izmir's Basmane Station to Selçuk in less than two hours (six departures daily).
Turkish Maritime Lines (Rihtim Cad. 1. 212/244-0207 for information. www.tdi.com.tr/eng/denizyollari.shtml).