Phou Bia (Lao: ພູເບັ້ຍ) is the highest mountain in Laos and is located in the Annamese Cordillera, at the southern limit of the Xiangkhoang Plateau in Xiangkhouang Province. Owing to its altitude, the climate is cold and the area around the mountain is mostly cloudy. Although no snow has been reported for decades, it is documented that as late as the first years of the 20th century, snow fell occasionally on its top.
On 10 April 1970, an Air America C-130A aircraft crashed into the mountain. The area is remote, covered with jungle, and has been used by Hmong guerilla soldiers. In 1970s, ca 60,000 Hmong supporting FAC operations took refuge at the Phou Bia massif. There have been reports of smaller Hmong hideouts in the area as recently as 2006.