For a bookable astronomy visit, use Yeongcheon’s Bohyeonsan Astronomy Science Museum in Jeongak-ri. It is a city-run visitor facility at the foot of the mountain; the research observatory on the summit is a separate site with limited public access.
Reserve the public museum session
The Science Museum operates 14:00–22:00. Adult admission is ₩4,000; teenagers pay ₩2,000. Book at least one day before your visit through the museum reservation page. The visitor listing says it closes on Mondays and public holidays. Its session combines astronomy exhibits, a planetarium and telescope viewing; check visitor details before choosing a time.
Do not confuse the two observatories
The mountaintop Bohyeonsan Optical Astronomy Observatory is a research facility, not the public museum. Public events at the summit observatory run on a separate schedule from museum reservations. If the museum is your evening anchor, keep the mountain road out of the same after-dark plan. See the city’s access information for the research observatory.
Find a Yeongcheon base for the return after your reserved session.