Termy Mszczonów

Termy Mszczonów is a complex of five pools in Mszczonów in the Mazovia region, about 40 kilometres from Warsaw, run by the municipal sport and recreation body OSiR Mszczonów. The Polish Wikipedia article on the town records that the geothermal pool complex was ceremonially opened on 28 June 2008. The operator describes the site as a pool complex using unique fresh thermal springs and as a tourist attraction of Mazovia aimed at visitors of every age, and notes that it was built with the population of central Poland in mind.

The thermal water has been extracted since 1997 through the Mszczonów IG-1 borehole from a depth of 1,602.5 metres, in Lower Cretaceous sandstone. Measured at the surface the water is 42 °C. Its total mineralisation is 459.79 mg/l, dominated by calcium and magnesium bicarbonates, and the operator states that this is a mineralised drinking water unique in Mazovia for being drawn from such a depth. Published constituents include 60.12 mg/l calcium, 13.37 mg/l magnesium, 29.00 mg/l sodium, 8.00 mg/l potassium, 320.95 mg/l bicarbonate, 9.39 mg/l chloride and 0.19 mg/l fluoride. Because the mineral content is low by spa standards, the water is closer to fresh warm water than to the strongly mineralised brines used at many Polish thermal baths.

The pools are fed with water at between 26 and 34 °C. The complex consists of five pools: two year-round thermal pools, a recreational pool, a sports pool and a children's pool. Water slides, saunas, a salt grotto, beach volleyball courts and a children's playground complete the site; the operator does not publish a sauna count.

The complex opens daily from 09:00 to 22:00 between 1 July and 31 August, and from 09:00 to 21:00 between 1 September and 30 June. It is closed on 24 and 25 December, on 1 January, on the first day of Easter and on 1 November, and opens 09:00 to 14:00 on 31 December. A technical shutdown was scheduled from 7 to 26 April 2026, during which the site was closed.