Keşan is a city in Eastern Thrace, NW of Turkey. It’s located on a junction on which roads from four cardinal directions intersect (west from Greece, east from Istanbul, south from Canakkale/Aegean coasts, and north from Edirne).
This is the first major Turkish town on the highway when arriving in Turkey from Greece. It’s only about 20 km away from the border. From Istanbul in the east, it’s about a three-hour drive away (about 210 km) on a straight and wide road (two lanes per direction).
There are lots of buses (about once every 30 minutes) from Istanbul and Edirne during daytime. Keşan’s main bus station (otogar) is located in the outskirts of the city, near a highway, but there are free courtesy minibuses (which your bus company provides) and public minibuses to take you from there to city centre.
There are two supermarkets (big-box store type) located on the opposite sides of major crossroad there.