About 15 minutes south of Kewaskum, Lizard Mound County Park (formerly a state park, now operated by Washington County) preserves a striking group of prehistoric earthworks in a quiet oak forest. A short loop trail runs past the mounds, with interpretive signs explaining their shapes — most clearly recognisable when leaves are off the trees.
The mounds rise only a foot or two above the ground and are easy to miss until you train your eye, but the site rewards a slow visit. Best in early spring or late autumn for visibility. No admission charge.