The existence of the Castrum is documented since the time of the lord Guglielmo II (about 1188), but it is assumed that exists already in the centuries IX and X. In 1193 the castle defended by Ruggero of Chieti, knew how to resist and definitively discourage the offensive of the combined army of Enrico VI and Roffredo of the island (Vairanum acriter impugnans in profecit ). In 1437 Vairano was sacked by the army of the Patriarch Vitellesco mandate from the pope Eugene VI. In 1461 the farmhouses and the castle knew the destructive fury of the army of Marino Marzano who left Vairano, according to the chronicles of the time, “depopulata et dehabitata”.
Between 1491 and 1503 the castle was completely renovated by the feudatory Innico II d’Avalos. The fortress is composed of 4 towers, of which the most massive is called tower “mastra”. The interior is now completely mere ruin, but are still visible the subdivision of the planes, the kitchens, the prisons and the ancient cistern. The village is surrounded by walls interspersed with 14 towers. Three doors provide access to the village: Olive port, carries means or noon and Porta Castello or S. Andrea. Inside you can visit the ancient church of S. Thomas the apostle (XIV century), while just outside of the walls, recently restored, is located the church of S. Maria di Loreto (XVI century).