Konur Alp Gazi was a close comrade and frontier warrior of Osman Gazi and Orhan Gazi who in 1323 conquered Düzce and its surroundings from the Byzantines; the region bears his name as 'Konuralp'. His tomb in the Konuralp neighborhood of Düzce next to the historic Konuralp Mosque was restored in 2020 and is open to visitors. (Sources: Düzce Directorate of Culture and Tourism; Düzce Governorship.)