As beautiful as Bath is, it is more interesting underground. This is where the ruins, the gods, and the waters are: the steps to the temple of Sulis Minerva near the Pump Room, the Victorian tunnels, and, in the eerie plant room below the Gainsborough Bath Spa Hotel, the water from the ancient springs, waiting to be purified before it flows into the Gainsborough’s private baths.
The three springs of Bath – The Cross, the Hetling and the King’s – formed when rainwater fell on the hills 10,000 years ago, descended 2500 metres and rose through the limestone to the city. They produce one million litres a day, at a temperature of 45-46 degrees, and are filled with minerals: sodium; calcium; sulphate; chloride; magnesium; iron. They have, over the centuries, been assumed to cure anything from infertility to melancholia.
According to Geoffrey of Monmouth the magic water cured the leprous Prince Bladud, a prince of the Celts, who approached the springs – they were mud then – with his similarly leprous pigs. He was cured, later to return to his kingdom, become the 9th king of the Britons and sire King Lear. This is the foundation myth of Bath. Bladud founded the city in 863 BC, built a temple to the Celtic goddess Sul and is commemorated with a statue – with a cheerful pig – in the gardens by the river. All visitors follow in the footsteps of Bladud. The Romans founded the city of Aqua Sulis here in 43 BC and built the temple to Sulis Minerva and the Roman bath house. That is the whole point of Bath; and it is the point of this soaring new hotel. Everything comes back to the waters.
Matthew Ryder, the engineer, shows me the plant room. The water is owned by the people of Bath, and the Gainsborough Bath Spa Hotel pay for a licence to extract it. There are three boreholes. One is for the vast Thermae complex, the city’s newish bath house, in which you can bathe outdoors on the roof and count the stone angels on Bath Abbey. Their plant room, he says, is vast: it has the same footprint as the whole complex. Another borehole feeds the Roman Baths, in which no one should bathe, unless a maniac longing for death. The water is not treated or filtered. It is bright green. It was available for bathing by NHS prescription after the war but no more. One of the last bathers contracted meningitis and died. The Gainsborough Bath Spa Hotel, which used to be a hospital, and now is a grand hotel with the best spa private waters in the city – and so the country – built a third. They drilled down at an angle – there is less chance of fracturing the rock – and put a stainless-steel lined pipe in. Then they pump up the water.
'We’ve got so much compliance to even get the water out of the ground,' he says, indicating pipes, barrels and taps. 'We sample it hourly, daily, weekly, monthly yearly'. He filters it through sharp sand – 'if you put it under a microscope, you see it locks together and takes any impurities out of the water'. Then there is a UV process, 'which kills anything else left in there'. He adds minimum chlorine and acid – essential for public bathing – 'and away we go'. He loves the plant room and its water. He calls it, fondly, 'magic water'.
This hotel was once a hospital. Hotels that were once hospitals are strange places. I have stayed in the terrifying San Clemente Palace Hotel, on an island in Venice. It had long, sullen corridors and when I learnt that it was, for several hundred years, a psychiatric hospital for women I was not surprised. But somehow the long corridors and high ceilings of a former hospital suits the Gainsborough because it is a plush and pleasing kind of hospital: a solus per aqua (“health through water”), or spa. The suites are plush and very comfortable, but not ornate. Everything comes back to the waters.
I go through the corridors and down to the baths. There are sumptuous, almost new and neo-Classical, which suits them. There are small pools; a large pool; showers, fountains and taps. The waters are hot, not warm, and made by the earth. They seem to have a quality of holding you up. The sensation is incredible. I think of Prince Bladud’s pigs, Roman soldiers bathing their battle wounds and infertile medieval Queens. They all used these waters. Then they pour out under the abbey, into the River Avon, and away.