The name of this ancient village derives from Vignoni, already famous castle in XI century, whose traces dominate the hill over the village.The thermal water where used by the Romans ,archaeological artfacts are found in the Chigi collection of Siena, National Archaeological Museum. A porch-type bridge passes over the waters flowing from the bath towards the termal establishments and subsequently going on to feed a series of mils situated along the steep edge sloping down towards the river an area that may now be visited thanks. Lo extensive resounding carried out by the St. Quirico Council (Watermill Park).

It is known that Catherine of Siena stayed in Bagno Vignoni several times, taken there by her mother in an attempt to dissuade her from taklng the Order.

Other illustrious persona ges such as Pope Pio Il Piccolomini and Lorenzo the Magnifilcent, who sta yed for a period 1490, also bear witness Lo the popularity of the baths.

The vicinity of the bath to the Via Francigena, scene of the heaviest flow of pilgrims of their way to Rome, persueded the less hurried of the travellers to make the acquaintance of and to use the spa waters. Mention is made of this in Michel de Montaigne's travel diary in 1581.

During l6th tury the waters and their curative propert­ies inspired the Sienese scholar Lattanzio Tolomei, to write the Greek verses dedicated to the water Nymphs engraved on the marble tabled now enclased on a pillar in St. Catheri­ne's open gallery.

The Commune of Siena had always kept the thermal treatments carried out in the zone under strict control and indeed two articles of the City Constitution are dedicated specifically to the Vignoni establishment, prescribing the division of the men's and women 's bath with the cost of the operation to be borne half by the inhabitants and the hotel keepers of the zone and the other half by the inhabitants of the Val d'Orcia castles; room prices were also estab]ished.

During the same century new interest and studies relating to mineral waters and the spa bath flourished. Among the authors who spoke of Bagno Vignoni was the physician Andrea Bacci who, visiting the bath in person in 1548, praised the munificent hospitallty of the Amerighi famlly. In 1592 the Grand Duke granted the said family the use of the gabelle of the bath, on the understanding that they in turn would arrange for the necessary manteinance; this agreeme­nt became permanent in 1599, on the same condition together with the obligation of keeping a bakery a butcher's shop and a tavern in Bagno, as well as the staff required for carrying out the spa treatments, whilst the annual emptying of the bath in May saw the Amerighi family authorised to call upon the inhabitants of the Val d'Orcia for this puorpose. The small chapel dedicated to St. Catherine built in the center of the porch overlooking the termal pool, was cons­tructed by this fami]y.

In 1677 the Gran Duke Cosimo III enfeoffed St. Quirico d'Orcia to Cardinal Flavio Chigi, together with the lilttle villages of Vignoni and Bagno Vignoni; the thermal establishment, together with three mills, eight houses, a tavern and a certain amount of land thus passed into the hands of the Chigi family and their discendents to whom a part still remains in property.

Nowadays Bagno Vignoni is well-known and appreciated the world over as an esteemed thermal locality situated in the heart of the Val d'Orcia Artistic Natural and Cultural Park, a context of almost immuted beauty through the century