Beja Air Base (Portuguese: Base Aérea de Beja; IATA: BYJ, ICAO: LPBJ), designated as Air Base No. 11 (Portuguese: Base Aérea Nº 11, BA11) is one of the most important military airbases in Portugal, 9 km (5.6 mi) northwest of Beja, 100 km (62 mi) north of Algarve. It is used by the Portuguese Air Force and has two parallel runways in the 01/19 direction, the biggest being 3,450 m × 60 m (11,320 ft × 200 ft).