Tam Điệp pass
20°07′53″N 105°51′30″E / 20.131349°N 105.858225°E
The Tam Điệp pass (Sino-Vietnamese name: Đèo Tam Điệp, demotic folk name: Đèo Ba Dội) is the name of the three passes between ancient Thăng Long and Ninh Bình and Thanh Hóa provinces.
20°07′53″N 105°51′30″E / 20.131349°N 105.858225°E / 20.131349; 105.858225
The Tam Điệp pass (Sino-Vietnamese name: Đèo Tam Điệp, demotic folk name: Đèo Ba Dội) is the name of the three passes between ancient Thăng Long and Ninh Bình and Thanh Hóa provinces.