I'd give this ruin at least an hour, more if they have an event going on. We enjoyed exploring the castle and imagining what it must have been like when active. There's lots of neat sculpture done by contemporary black smiths through out the castle. We did this as part of a day trip from Olomouc, spending most of the day at the Wallachian open air museum and stopping hear on the way back. It adds 20 minutes driving and that is through lovely countryside and attractive villages.