Salt mine
Speleotherapy
Salt lakes & mud
Slănic Prahova
A salt mine turned into an underground sanatorium at ~210 m depth — salty air for the respiratory tract, plus hyper-concentrated salt lakes and healing mud.
At a glance
Slănic Prahova, in Wallachia, has mined salt for over 300 years. The old Unirea salt mine has been converted into an underground sanatorium at about 210 m depth: the salty microclimate is traditionally recommended for chronic lung and respiratory conditions (speleotherapy). Above ground, hyper-concentrated salt lakes — Baia Baciului, Grota Miresei, Baia Verde and Baia Roșie — and healing mud complete the picture. Towering over it all is the salt mountain (Muntele de Sare), a geological monument unique in Europe.
Well suited for
- Respiratory tract (speleotherapy)
- Rheumatism & skin conditions
- Salt-lake bathing in summer
Less suited for
- Acute infections & fever
- Those seeking warm thermal bathing
01Overview & history
Slănic Prahova lies in Prahova County, in the historic region of Wallachia (Muntenia), on the edge of the Prahova sub-Carpathian hills north of Ploiești. Salt has been mined here for over 300 years — the town's story is inseparable from its salt.
Its centrepiece is the old Unirea salt mine: once industrial extraction ended, the vast chambers at about 210 m depth were turned into an underground sanatorium. Above ground, the collapse and dissolution of former salt pits created the famous salt lakes, while the salt mountain (Muntele de Sare) remains as a geological natural monument unique in Europe.
02Remedy & composition
The main remedy is the salty underground air of the Unirea mine — a stable, germ- and allergen-poor microclimate for speleotherapy. This is complemented by the hyper-concentrated salt lakes with sodium-chloride water (salinity up to about 260 g/l) and by healing mud.
| Property | Detail |
|---|---|
| Main remedy | Salty underground air (speleotherapy), ~210 m depth |
| Salt lakes | Baia Baciului, Grota Miresei, Baia Verde, Baia Roșie |
| Grota Miresei | formed by collapse, ~1,300 m², up to ~32 m deep |
| Salinity | Sodium-chloride water, up to ~260 g/l |
| Other remedies | Healing mud (peloid) |
Figures are for orientation only. Exact climate and analytical values vary by lake, chamber and facility.
03Indications & contraindications
Traditionally recommended for
- Chronic respiratory and ENT conditions (speleotherapy)
- Rheumatic conditions
- Neurological complaints of the musculoskeletal system
- Metabolic and skin conditions
- Gynaecological complaints (mud packs)
Caution / seek medical advice with
- acute infections
- fever
- severe cardiovascular disease
- open wounds
04Spa treatments
| Treatment | Description | Duration |
|---|---|---|
| Speleotherapy | Time spent in the salty underground air (Unirea mine) | 2–4 hrs |
| Salt-lake baths | Bathing in the hyper-concentrated salt water of the lakes | 10–20 min |
| Warm mud packs | Healing mud on joints, back or targeted areas | 20 min |
| Electrotherapy | On medical prescription | individual |
| Breathing exercises | Respiratory exercises in the mine's microclimate | 20–30 min |
05Accommodation
In and around Slănic Prahova there are guesthouses, pensions and holiday apartments — from simple to comfortable. For a wider choice of hotels, the nearby city of Ploiești is a good option, and day trips from Bucharest are also feasible.
Guesthouses & pensionsLocal style, family-run, close to mine and lakes
Hotels in PloieștiWider choice, good connections
Specific accommodation with prices and booking links to follow shortly.
06Prices & opening hours (guide)
| Service | Guide price |
|---|---|
| Day ticket, salt mine | from approx. €6–12 |
| Reduced (children / seniors) | from approx. €3–6 |
| Mud pack (single) | from approx. €6–10 |
| Guesthouse overnight (double room) | approx. €30–60 / night |
Guide prices, as of 2026. Bathing in the salt lakes is seasonal (summer); prices and opening hours vary by facility — please confirm on site.
07Nearby
- Salt mountain (Muntele de Sare) — a geological monument unique in Europe, right by the town
- Prahova highlands — hills and walking trails of the sub-Carpathians
- Ploiești & Bucharest — city, culture and access to the airport (~110 km)
08FAQ
What is the speleotherapy in the salt mine?
The old Unirea salt mine was converted into an underground sanatorium at about 210 m depth. The salty microclimate, with a stable temperature and salt-rich air, is traditionally recommended for chronic respiratory conditions.
Can you bathe in the salt lakes?
Yes, in summer. The hyper-concentrated salt lakes (including Baia Baciului and Grota Miresei) make the body very buoyant and are traditionally used for rheumatic complaints. The mine itself is accessible all year round.
How far is the nearest airport?
Bucharest Airport is about 110 km away. From there, Slănic Prahova is easily reached via the Ploiești area.
When is the best time to visit?
The salt mine is accessible all year round, as its underground climate is constant. For bathing in the salt lakes, summer is the best time.
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