The Cả pass (Đèo Cả) is a mountain pass in Phú Yên Province, Vietnam. The mountains are known as the Cả pass mountains (núi Cả Đèo). Historically the Cả Pass was the second most difficult col in Vietnam after Hải Vân Pass. In 1611, the Nguyen pushed their border down to Cả Pass.
- Vietnam economic times: Volume 159 Viện kinh tế thế giới (Vietnam) "Located on a granite block of around 20,000 hectares with the highest mount standing at more than two kilometres above the sea, Ca Pass was the second most difficult col in Vietnam, after Hải Vân Pass. To the north. Da Bia Mountain stood ..."
- Views of seventeenth-century Vietnam: Christoforo Borri Page 21 Olga Dror, Keith Weller Taylor, Cristoforo Borri - 2006 "In 1611, the Nguyen pushed their border down to Ca Pass to include the modern province of Phú Yên. "