Başoğlu is a neighborhood in Kaynarca District, in Sakarya Province, Türkiye. Başoğlu lies at 49 m above sea level. It has 293 inhabitants. The nearest city is Ferizli, 25 km to the southeast. Beaches nearby: Kefken (14 km), Kumcağız (14 km), Kumcağız (15 km). Among the landmarks around are SM UC-13 (8.7 km), Kefkenada Lighthouse (13.6 km) and Sangarius Bridge (46 km).