İznik is a municipality and district located in the Bursa Province of Turkey. Covering an area of 753 km², the town has a population of 44,236 as of 2022. It is situated in a fertile basin at the eastern end of Lake İznik, bordered by ranges of hills to the north and south.
The modern name of the town is derived from its location on the site of the ancient city of Nicaea. Geographically, it is positioned approximately 90 kilometres southeast of Istanbul as the crow flies, though it is roughly 200 km away by road via the Gulf of İzmit and 80 km from Bursa.