Where was The Secret Book filmed?
2006 film
The Secret Book (2006) was filmed in Ohrid, Bitola and Balchik, 3 places named in its Wikipedia article's Location section, in North Macedonia, Bulgaria. Wikidata itself records the shoot only as Bulgaria. Each place says where its claim comes from.
Places per Wikipedia's Location section
Wikipedia’s Location section names 3 places. Each links to the sentence that says so.
Recorded only at country level
Also filmed in Bulgaria, but the exact places are not known, so they are not on the map.
Filming locations that are mapped there: Bulgaria