From a purely artistic standpoint, this is a remarkable museum of wax figures that are so uncannily good they transcend kitsch. The sculptor Vrellis, who died in 2010 and left behind this life's work, was a true master. From a practical standpoint, it's a frustrating place if you're not versed in Greek history, as there is no signage. The website, however, has plenty of detail in English. Go for the art of it, and read up before or after.
A visit takes less than 30 minutes, but you must go through in groups, which may require a wait. The museum is a short drive south of Ioannina.