Llera is situated on the banks of the Guayaleyo River, part of the
Panuco River system. The Guayalejo is clear and fast-running and is popular for recreation, including
kayaking. The municipality extends from the plains to the higher elevations of the
Sierra Madre Oriental west of the town of Llera.
Tamaulipan mezquital, a low growing, thorny shrubland, is the most common vegetation. Most of the municipality has a semi-arid climate with hot summers and warm winters.(BS climate in the
Köppen system), although higher elevations are cooler and moister. Freezes are rare at lower elevations, but common in winter at elevations of more than . (173 km2) of the municipality is included in the
El Cielo Biosphere, a mountainous area noted for being the northernmost extension in Mexico of the tropical
Veracruz moist forests and sub-tropical
cloud forests. ==References==