San Martín Tower stands near the Ayuntamiento and the Cathedral, making it the most centrally placed of the four UNESCO Mudéjar towers. Dating to 1316, it is probably the oldest, and its decoration — geometric brick patterns and ceramic tile inlays — set the vocabulary that the later towers in Teruel would follow.
Unlike El Salvador, San Martín cannot be climbed, but it can be closely examined from the street. The lower sections of the tower straddle the pavement, as was typical of these gate towers — they were originally built over city roads and served as entrance points to different quarters. It stands a short walk from the Ayuntamiento on the plaza of the same name.