Having never heard of a “Sea-tox”, I was intrigued. Will I be de-toxifying in the sea itself? Is the Spa made entirely out of seawater? Are the therapists animated Disney sea creatures and if so, will I finally turn into Ariel (my childhood dream…)?

These were my first thoughts on arriving at the Hotel Bellevue, Croatia, part of Lošinj Hotels & Villas, a member of Preferred Hotels and Resorts.

My second thought was that suddenly, I had the lungs of a superhero. This was the cleanest and sweetest air in the world. It turns out that the seawater here has an unusually high concentration of minerals, there are over 200 sunny days per year – something my London brain struggles to grasp, 1,200 species of plants – 230 medicinal – and Aleppo Pines emitting terpenes, all of which makes this the “healthiest air on the planet”. And this is before you even get to the front desk of this spa resort which is destined to be known as the jewel of Croatia’s wellbeing.

The Bellevue Spa Clinic offers a complete ecosystem of wellness, just…