At 36 miles long and 618 feet deep, Seneca Lake is one of the deepest bodies of water in the United States. It seldom freezes over and is renowned for its superb lake-trout fishing. Given to sudden, capricious gusts of wind, it’s the most mysterious of the Finger Lakes.

Ever since the days of the Native Americans, area residents have reported strange, dull rumblings coming from Seneca’s depths. The sounds are usually heard at dusk in the late summer or early fall and are most distinct midway down the lake. The Native Americans believed that the rumblings were the voice of an angry god; early settlers considered them omens of disaster; science attributes them to the popping of natural gas released from rock rifts at the bottom of the lake.

Whatever the cause, the dull rumbles—a sound much like gunfire—may have had some portent, for during World War II, a huge munitions depot and naval station was built along Seneca’s eastern shore. The naval station is now long gone, but the 11,000-acre Seneca Arms Depot remains.

Officially, it functions to “maintain and demilitarize ammunition,” but the herd of snow-white deer that roam the grounds can’t help but make you wonder. The deer can best be seen from Route 96A at dawn and dusk.

At the northern end of Seneca Lake lies Geneva, a historic town whose South Main Street has been called “the most beautiful street in America.” At the southern end is Watkins Glen, a rugged, 700-foot-deep gorge that’s been turned into a natural theme park.