Cayuga Lake is the long glacial lake that defines Ithaca's setting. The city sits at its southern end, where creeks tumble down the surrounding gorges before flattening into a waterfront of marinas, parks, and bird-rich marshland.
You do not need a boat to enjoy it, though being on the water helps. Walk or cycle the waterfront, visit the Cayuga Nature Center area, or drive the lakeshore for wineries and small villages. On clear days the lake seems to run north forever, which is exactly the kind of scale that makes the Finger Lakes feel different from ordinary upstate scenery.