Banyumasan (basa Banyumasan), also known by its autoglottonym Ngapak (basa Ngapak), is a dialect of Javanese spoken mainly in three areas of Java: the Banyumasan region in the westernmost part of Central Java province and surrounding the Mount Slamet mountain and Serayu River; a neighboring area inside West Java province; and northern region of Banten province. This area includes Cilacap, Kebumen, Banjarnegara, Purbalingga, Banyumas, Pemalang, Tegal, and Brebes regencies, together with independent cities within that region. Banyumasan is considered as one of the most conservative Javanese dialects (comparable to the Nuorese variety of Sardinian), retaining the phonology and some aspects of Old Javanese grammar in the modern language.
