Fort Ancient (33 WA 2) is a Native American earthworks complex located in Washington Township, Warren County, Ohio, along the eastern shore of the Little Miami River about seven miles (11 km) southeast of Lebanon on State Route 350.

Built by the Hopewell culture, who lived in the area from the 200 BC to AD 400, the site is situated on a wooded bluff 270 feet (82 m) above the Little Miami.

In addition, this is part of the Hopewell Ceremonial Earthworks, one of 14 sites nominated in January 2008 by the U.S. Department of the Interior for potential submission by the United States to the UNESCO World Heritage List.

The shoulder blades of deer, split elk antlers, clam shell hoes, and digging sticks were used to loosen the dirt, and baskets holding 35 to 40 pounds were used to carry and distribute the soils in building the earthworks.

The southwest mound of the four is interpreted to have functioned as a point that aligned with gateway openings in the embankment walls to mark significant solar and lunar events.

Topics include North America's earliest people, the development of agriculture, and the impact of Europeans who migrated to the area and came into conflict with the Native Americans then living in region.