The most compelling day trip from Hamilton lies about 15 miles to the southwest: the Fernald Preserve, a 1,050-acre nature preserve built on the cleaned-up grounds of a former Cold War uranium processing facility. The on-site Fernald Learning Center tells the full story of the site's nuclear past and the $4.4 billion remediation effort that followed. Trails through restored prairie and wetland are free and open daily — it's one of Ohio's more thought-provoking outdoor experiences.