Heihe Aihui Airport — Heihe, China

Heihe Aihui Airport uses the code HEK and serves Heihe, a Chinese city sitting directly across the Amur River from Blagoveshchensk, Russia, making it one of the more unusual China-Russia border crossing points. The airport supports domestic flights linking Heihe to larger Chinese cities, facilitating both trade-related travel and tourism tied to the city's distinctive cross-border relationship with its Russian neighbor. HEK is a relatively small facility, reflecting Heihe's modest population, but it holds strategic value given the remoteness of the region from major transportation corridors. Winters here are extremely cold, and the airport's operations reflect the seasonal rhythms of this far-northern Heilongjiang border city.