Where was Entrance to the Labyrinth filmed?

1990 Soviet miniseries directed by Valeriy Kremnev

Entrance to the Labyrinth (1990–) was filmed in Tallinn, Balchik, Tallinn Old Town, Pirita Convent, Saint Catherine's Monastery and St. Catherine's Passage, 6 places named in its Russian Wikipedia’s Производство section, in Estonia, Bulgaria. Wikidata records no filming location for it at all, so the article is the only recorded source. Each place says where its claim comes from.

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