Isunigu (also called Seneca, Esseneca, and Sinica) was a Cherokee town on the Keowee River, near present-day Clemson, South Carolina and Seneca, South Carolina. It was on the west side of the Keowee River, near the mouth of Coneross Creek, in today's Oconee County, South Carolina. Nearby, on the east side of the Keowee River, was the "Hopewell" plantation of General Pickens, where the 1785 Treaty of Hopewell was signed.