It is a historic town on a flat plain on the east side of Lake İznik. The results of some researches prove that it has been a settlement since prehistoric times. The former Byzantine town of Nicaea, which is a walled city, still reflects its glorious past because it appears to be an open-air museum.
Having the traces of ancient, Byzantine and Ottoman periods, it is a touristic center today. The walls around the city and the gates, the theatre, the St. Sophia Church (the Mosque of Orhan Ghazi), which is now a museum, the Haci Özbek Mosque, the Green Mosque, the imaret of Nilüfer Hatun, the Madrasah of Süleyman Pasha and the tombs of the Vizier Çandarlı family are major monuments worth visiting.
İznik, a pretty town in the province of Bursa today, has been inhabited by several cultures through its long and turbulent history. It was a model of town-planning in ancient times and became an important religious center in Roman times. The assembly of the first ecumenical council in İznik, in 325 B.C., proves its importance. After a short period of Seljuk domination, it served as the Byzantine capital from 1204 to 1261.
İznik was captured by the Ottomans in 1331 and rebuilt because it was in ruins as a result of many battles.
İznik has been the center of tile industry since the 15th century. İznik tiles are distinctive with the use of flower patterns instead of geometrical designs and the colour of coral red.