This is the most extensive study of its kind – almost 28,000 local names from the Kyustendil region have been collected and explained, of which about 4,000 are included in this first volume. A phonetic characterization of the names has been made, their structure and grammatical features have been discussed. A map of the dialects in the Kyustendil region has also been included. The collected local names contain information not only about the language, but also about the history, archeology, population movement, and its material and spiritual culture. Many of them are associated with various traditions and legends.