On May 4, 1970, Ohio National Guard soldiers opened fire on students at Kent State who were protesting the U.S. invasion of Cambodia. Four students were killed and nine wounded. The May 4 Visitors Center on the Kent State campus tells that story with care — a well-designed museum that contextualizes the shootings within the broader Vietnam War era and antiwar movement.
What makes the site unusual is that you are standing on the actual ground where it happened. The parking lot remains, marked by low memorials indicating where each student fell. The distance between the guardsmen's position and the students is shorter than most people expect. Walking it changes your understanding of that day.
Admission is free. The visitors center is on the main Kent State campus, easily reachable on foot from the university's central areas.