Craig Ty-Isaf is a small hillfort in Baglan community, Neath Port Talbot, in South Wales. It is one of three hillforts on the area of hillside known as Mynydd y Gaer, and is within Briton Ferry Woods. The hillfort is on the SW side of the hill, overlooking Baglan, an oval enclosing some 0.2ha. A broad rubble bank forms the oval enclosure, and on the east two further banks mean that the area of banks and ditches encompasses a much larger area for the site as a whole, which is a Scheduled Monument. There are various internal features thought to be the result of more recent test cuts for mineral extraction.