The Algeciras Fault is a right-lateral strike-slip system running through the Eastern Cordillera of Colombia, in the departments of Huila and Caquetá, forming part of the broader Eastern Frontal Fault system. It stretches for well over 200 kilometres along the mountain front southwest of Bogotá.
The fault accommodates the northeastward escape of the North Andean Block as the Nazca and Caribbean plates converge against South America, slipping at several millimetres per year. Its trace produces classic strike-slip landforms such as offset streams, linear valleys and pressure ridges through the Andean foothills.
The Algeciras Fault ruptured in a series of earthquakes in 1967 with magnitudes near 7, causing damage and casualties in the Huila region. Continued microseismic activity confirms it is one of the most active faults in Colombia and a key contributor to seismic hazard in the country's central Andes.