Western Region (Xu Doai) is the area to the west of Hanoi, which includes the former provinces of Sơn Tây and Vĩnh Yên, now part of Hanoi and Vĩnh Phúc respectively. Historically a poor region, famous for Mt Ba Vi, Mt Tam Đảo, the Red River and Black (Đà) River. Sites of interest include Tây Phương, Thầy and Trăm Gian pagodas. Historical figures: Phùng Khắc Khoan and Nguyễn Trực.
Common saying: Cô gái Sơn Tây yếm thủng tầy giần; răng đen hạt nhót, má hồng trôn niêu (the Son Tay girl wears a blouse with as many holes as a sieve, her teeth as black as an olive pit, her cheeks as rosy as a clay pot).
