The most rewarding day trip is to Sviyazhsk, the 16th-century island monastery town founded by Ivan the Terrible upstream of Kazan and now a UNESCO World Heritage Site. A boat from Kazan's river terminal makes the four-hour Volga journey there in summer; minibuses run year-round in about an hour.
Raifa Monastery, 25 kilometres west of the city in a forested lake setting, is the second most popular trip — a working Orthodox monastery in pale-blue baroque buildings around still water. Day tours combine it with a short stop at the Volga-Kama Nature Reserve nearby.
For something further afield, Bolgar is the ruined capital of the medieval Volga Bulgar state, 180 kilometres south of Kazan and best reached on a long-day organised tour or river cruise. The 13th-century mosque ruins, mausoleums, and minaret are a unique piece of pre-Mongol Tatar heritage and another UNESCO site.