Çanakkale is the natural base for two of Turkey's great battlefield destinations — the World War One Gallipoli sites on the Thracian (European) shore of the strait, and the ancient city of Troy about 30 km south. Both deserve a full day each and most travellers stay two or three nights in the city to do them justice.
The city itself has a working waterfront, a startlingly large 2004-film prop Trojan Horse on the seaside promenade, two Ottoman fortresses on either side of the narrowest point of the strait, and a couple of excellent small museums. It is a relaxed place to wander between hard-going battlefield visits.