Located under the Nuncio Viejo street, these ruins are former Roman baths and a part of the city's sewage system.
More information on Toledo's official website http://www.toledo-turismo.com/en/roman-vaults-of-nuncio-viejo_143
Address 19 Calle de Nuncio Viejo, Toledo 45002, Spain
Coordinates 39°51'30.125" N -4°1'30.108" E