Masse di San Sisto, also known as Pozze di San Sisto, or Terme di Vetralla, or fonti di Pallino, are located to the south of the Cassia. The thermal area of the Masse di San Sisto is placed at the southern end of the thermal area of Viterbo, at the foot of the Monti Cimini, in the direction of Vetralla, where the remains of a large rectangular hall with niches and wall ruins are still visible. The archaeological remnants of the Terme del Masso or Massi di S. Sisto or Terme di Sant’Ippolito, are in the locality of Paliano: these well-preserved ruins, together with fragments of tiles, marble and terracotta spread in the surrounding fields, suggest that the complex was considerably extended.