Marmaris, which is a pleasant coastal resort, on the Southern coast, opposite the island of Rhodes, in Greece. Istanbul is the capital in the north. It takes 18 hours by bus from Marmaris to Istanbul, and is 800kms
If you are driving it will take you about the same as the roads are not all highways.
There are internal flights which you can buy on the day from Istanbul to Ankara, which is a bit closer to Marmaris.
There are also sail boats for hire, but they can't always go right up to Istanbul from Marmaris, so you would probably have to stop in Izmir. Turkey has reasonably good travel links however.
If you are driving it will take you about the same as the roads are not all highways.
There are internal flights which you can buy on the day from Istanbul to Ankara, which is a bit closer to Marmaris.
There are also sail boats for hire, but they can't always go right up to Istanbul from Marmaris, so you would probably have to stop in Izmir. Turkey has reasonably good travel links however.