The history of the town is linked to that of the two Franciscan Monks of Saint Matteo and Saint Maria di Stignano. Situated along the Via Sacra Langobardorum, they offered refuge to pilgrims travelling to Mount Sant’Angelo. The Sanctuary of Santa Maria di Stignano, about 4 kilometres away from San Marco in Lamis, dating back to the XIV century, has a sixteenth century façade in Abruzzi Romanesque style.
There is a sixteenth century portico in the interesting adjacent convent with a valuable portal of 1576. The Convent of San Matteo Evangelista, dating back to the IX-X century, was built on a pre-existing Longobard building of the VI century. An important Benedictine centre, in 1311 it was taken over by the Cistercian monks and in 1578 by the Franciscans.