"Wonder three - the hot pool, which is in the region of the Huich and encircled by a wall made of brick and stone and to that place men go during all seasons to be washed and to each, as it may have pleased them, the bath thus may be made according to his own will: if he may have willed, the bath will be cold, if warm, it will be warm."1,2
This wonder is likely to be a geological one - a geothermally heated pool3. The Hwicce were Saxons who's territory included the town of Bath4, so it seems likely that the pool in question are the geothermal baths there5,6,7,8.
The use of the hot springs at Bath predates the Romans, who combined the local British deity worshiped there Sul9 with their own Minerva. The Temple and Bath Complex dedicated to this double Goddess continued, probably to the 4th C when Pagan temples were closed down by the Emperor Theodosius*. The fact that temple pediment stones were reused as paving within the complex* seems to suggest the area continued to be used5, and evidence that hot water still flowed in a walled pool here during Saxon times (when our list was compiled) can be found in the Saxon poem about Bath "The Ruin"6.
Mood quickened mind, and a man of wit, cunning in rings, bound bravely the wallbase with iron, a wonder.
You may like to read about the the Myth and Science of this Wonder.