Caldes de Montbui in Catalan or Caldas de Montbui in Spanish, is a Spanish town and municipality in the comarca of the Vallès Oriental in Catalonia. It is situated in the upper valley of the Caldes river, and the highest point of the municipality is the peak of el Farell at 816 m. It lies about 30 km from Barcelona and it part of its metropolitan area. The hot springs have been exploited since Roman times, and the remnants of the Roman baths and other Roman buildings can still be seen.