Ciudad Tecún Umán is the municipal center of Ayutla, located in the San Marcos Department of Guatemala. It is situated in the southern part of the department along the Suchiate River, which serves as the natural border between Guatemala and Mexico.
The city is notable for its proximity to the Mexican border and its connection to Ciudad Hidalgo in the state of Chiapas. This link is facilitated by the Puente Rodolfo Robles, a combined road and rail bridge that spans the Suchiate River.