Line 22 (Pinggu line) of the Beijing Subway is a rapid transit line under construction in Beijing and Hebei Province.

Pinggu District, formerly Pinggu County (平谷县), lies in the far east of Beijing Municipality. It has an area of 950 square kilometres (370 sq mi) and a population of 457,313. The district is subdivided into 2 subdistricts, 14 towns, and 2 townships. It borders the Beijing districts of Miyun and Shunyi to the north and west, respectively, Tianjin's Jizhou District to the southeast, and in Hebei province, Xinglong County and Sanhe to the northeast and south, respectively.