Ten deposits, and four different kinds of evidence
Croatian law names peloid among five natural healing factors. Ten places on the Adriatic are said to have it. What stands behind each of those ten is not the same thing twice.
The list circulates. Ten or twelve places on the Croatian coast where the mud is called medicinal, repeated from article to article with the same sentences and the same numbers. What the list never carries is the part that decides whether any of it is true: who examined the mud, when, and what they wrote down.
The answer is uneven. One deposit has a hospital department working on it every summer. Three have papers in peer-reviewed journals. Two have a single sentence on an official page. The remaining four rest on travel copy quoting travel copy.
What the law calls it
Peloid is not a loose word here. The Health Care Act lists it among five natural healing factors, next to thermomineral water, seawater, naftalan and climate. A 2024 bylaw defines it as inorganic or organic matter formed by geological or geological-biological processes, applied as baths or wraps.
The same Act creates a category of facility — a peloid spa — which the Ministry of Health grants by decision. Two institutions are authorised to establish whether a natural factor is medicinal at all, and both were authorised on the same day, 11 March 2024: the Andrija Štampar School of Public Health in Zagreb and the Public Health Institute of Primorje-Gorski Kotar County.
The Ministry also keeps a register of health tourism. It publishes no entries. The category exists, the procedure exists, and there is no public way to say which deposit holds the status.
Where a hospital goes
One site differs in kind. The lagoon at Nin, beside Queen’s Beach, is the largest deposit of medicinal mud in the country — about 120,000 square metres, measured in a 2022 paper in Frontiers in Marine Science by researchers from the Faculty of Food Technology and Biotechnology in Zagreb and the Ruđer Bošković Institute. The figure circulates elsewhere as cubic metres, which is a different quantity.
Organised, medically supervised mud therapy has run there since 1965, and the same paper counts more than 20,000 patients since. The programme runs each summer from early July to the end of August, conducted by the Department of Physical Medicine, Rehabilitation and Rheumatology of General Hospital Zadar.
Nin was entered at the Academy of Medical Sciences in Zagreb in 1960 as a climatic and thalassotherapy location. That is a registration from sixty-six years ago, not a current ministerial decision, and the two are regularly reported as one.
Where the papers are
Makirina Cove near Pirovac is the most examined of them. A 2008 paper in Environmental Geology described its sediment as distinguished from other Adriatic sites by the absence of pathogenic bacteria, and a 2014 paper in Geologija found no coliforms or E. coli in what it tested.
Both findings are about samples taken on particular dates. The most recent published sampling is from around 2013, and the standard those authors cite asks for a check every ten years. The same 2014 paper measured chromium at 92 milligrams per kilogram along with elevated molybdenum, and concluded that further work is needed before use. That sentence travels less well than the one about bacteria.
Morinje Bay near Jadrtovac was characterised in 2012 in Environmental Geochemistry and Health. Its trace metals sit mostly within the range of unpolluted Adriatic sediment; copper, lead, zinc and arsenic run slightly higher but inside the limits the authors applied.
Meline, in Soline Bay on Krk, has no balneological paper but has something the other two lack — a reserve estimate. A county study cites the Croatian Geological Institute on 1,223 cubic metres of high-grade black mud and some 34,700 cubic metres of sandy peloid, worked up for a 300-bed spa that was never built.
Where only the copy is
The remaining six are thinner, and not thin in the same way.
Mostina at Privlaka and Lake Mir in Telašćica Nature Park each carry one sentence from an authority — the local tourist board in the first case, the park itself in the second, which mentions fango in the south-eastern corner of the lake and says nothing further about it.
Sabunike, Sapavac on Vir, Istruga on Korčula and Gornji Karin rest on travel writing. The phrasing runs close to identical across the sites that carry it, which makes them one source rather than several. Two details in that copy do not survive a check: no source describes a mud spring at Sapavac, and no geological source connects the Privlaka mud to the Nin deposit, though both are repeated widely.
Lake Mir earns one correction of its own. It is warmer than the surrounding sea in summer and colder in winter, which the park states plainly and the articles quoting the park tend to halve.
Four of them are protected
Morinje is a Natura 2000 coastal lagoon and a special habitat under fisheries rules that prohibit most fishing — not an ornithological reserve, as it is sometimes described. Soline Bay falls inside four ecological network areas, and the county study records damage already done by uncontrolled extraction. Karin Sea is a Natura 2000 site. Lake Mir sits in a nature park whose rules forbid collecting or removing material from habitats, with a ranger service and fines behind them.
None of that puts the mud out of reach. It does mean the difference between using it where it lies and carrying it home is a legal one rather than a matter of manners.
The Ministry keeps a register of health tourism but publishes no entries — so no deposit here is called officially recognised.
What is not settled
Which deposits, if any, hold the legal status of a peloid spa — the register exists and publishes nothing. Whether Makirina’s microbiology still reads as it did in 2013, since the standard its own authors cite asks for a fresh check every ten years. What is actually in the Nin mud — no published composition table exists, and the sulphur-calcium-magnesium line in circulation comes from promotional copy. And nothing above describes what any of this does to a body: that question belongs to the department in Zadar, not to a directory.