The Kyrkhlyar ('forty') cemetery in Derbent is the oldest active Muslim cemetery in Russia, known for forty chest-shaped tombstones traditionally identified as forty companions/warriors martyred during the early Arab conquest. Tradition links them to the sahabi Salman ibn Rabiah al-Bahili's 7th-century Caucasus campaign. NOTE: the 'companions of the Prophet' attribution is a traditional/devotional identification resting on medieval Arabic narratives and the local Derbent-name chronicle, not on archaeological or epigraphic verification (the motif of 'forty' is a recurring votive theme across Islamic-Turkic geography). The cemetery's antiquity and martyr-veneration are genuine; the precise identities are pious tradition. (Sources: English Wikipedia 'Kyrkhlyar'; goldtrezzini.ru nomination file)