Boulder Bay is located on the Kangarutha Track, south of Tathra, within Bournda National Park. The bay is sided by two rocky coast lines that funnel the water to the sandy beach. The sand of Boulder Bay is lower on the beach and the area behind this is covered in rounded rocks in a variety of sizes. Boulder Bay Creek runs into the bay but is usually a dry creek bed at the back of the beach. Access to Boulder Bay is by the Kangarutha Track.