A sacred place of worship, Candi Sukuh will give you a better understanding of the area's spiritual leanings. Take a few moments to learn about the significance of this site to the local people.
You'll be spoiled for sightseeing choice when staying in East Java. Candi Sukuh is a good place to kick off here, but there are loads of other worthy places to consider. Wisata Bukit Sekipan, Grojogan Sewu Wafterfall, and Sukuh Temple are close to the place of worship and will fill in your day nicely.