Siebentäler Therme

The Siebentäler Therme stands at Schweizer Wiese 9, 76332 Bad Herrenalb, a spa town of about 7,700 people in the Landkreis Calw in the northern Black Forest. It is operated by Stadtwerke Bad Herrenalb GmbH, which gives the establishment's full legal name as "Siebentäler Therme -Mineraltherme-".

According to the Stadtwerke, drilling in 1963 on the Schweizer Wiese — the same plot the bath stands on — struck healing water at a depth of 600 metres; a drinking pavilion was built in summer 1965, and healing water flowed from the tap there by September 1965. The Stadtwerke give the formal designation of that water as a fluoride-bearing sodium-calcium-chloride-sulphate water and its analysis as sodium 606.4 mg/l, calcium 168 mg/l, chloride 872 mg/l, sulphate 535 mg/l and fluoride 3.07 mg/l; the water counts as a medicinal product, is subject to regular quality control and is de-arsenised. It is a named, analysed mineral source in a documented borehole, not heated tap water dosed with salt. The operator gives no source temperature, discharge rate or thermal certificate, and describes thermal springs at Bad Herrenalb only as long suspected: "Schon vor langer Zeit wurden Thermalquellen in Bad Herrenalb vermutet". The thermal bath built on the borehole opened in 1971, at which point Herrenalb became Bad Herrenalb. The operator calls it a Mineraltherme; without a source temperature it cannot be said whether the water is thermal in the strict sense.

The bath is closed for a full rebuild. The operator states that the therme is being revitalised and stays closed for the duration of the works, that the demolition phase is finished and the next construction phase has begun, and that the project is funded under Baden-Württemberg's tourism infrastructure programme (TIP). The operator expects a reopening in 2027. The design is by 4a Architekten Stuttgart.

Until the reopening the operator gives only essential information: no pool count, pool sizes, water temperatures, sauna cabins or opening hours. It describes the offer in outline as indoor and outdoor pools with warm water, saunas and steam baths, massages and wellness treatments and children's swimming courses, and says the water is particularly healthy and helps with joint and back problems. Of the rebuilt bath it says only that it will have an expanded range of themed worlds and a contemporary design. During the closure the town's other bath is the Waldfreibad, a separate open-air pool also run by the Stadtwerke.