Photo by Karol Czinege on Pexels
🇸🇰 Slovakia · Košice Region (Michalovce District, Zemplínska šírava)
Photo by Karol Czinege on Pexels
🇸🇰 Slovakia · Košice Region (Michalovce District, Zemplínska šírava)
♨ Temperature
40°C
⛰ Altitude
—
⚗ pH
—
💧 TDS
—
🌊 Flow rate
—
📅 Established
Local warm spring first documented in 1336; geothermal well GTH-1 deepened in 2012
✓ Verified on 2026-07-31
Thermal Šírava Spa Resort is located in the village of Kaluža, close to the shore of Zemplínska šírava, eastern Slovakia's large reservoir lake. Its geothermal well (GTH-1) was deepened to 940 meters in 2012 and delivers water at around 40°C with total mineralization measured near 12,684 mg/l — a neutral, chloride-sodium type water with notably elevated bicarbonate, fluoride, iodide, lithium and boron content, plus dissolved hydrogen sulfide, officially classified as natural healing water under Slovak Ministry of Health regulation. A warm spring in the area was already recorded in writing in 1336, and local legend attributes its discovery to a nobleman's servant who found a spring that never froze even in winter — geological dating puts the water itself at 6,000 to 10,000 years old.
A warm spring in the Kaluža area was documented in writing as early as 1336, with local legend crediting its discovery to a nobleman's servant who noticed a spring that never froze in winter. The modern geothermal well, GTH-1, was deepened to 940 meters in 2012, unlocking the highly mineralized water now used at the resort; geological analysis dates the water itself at 6,000 to 10,000 years old.