Trpanj's lagoon Blace is covered in therapeutic mud. According to the research carried out by the Rehabilitation and Physical Medicine Institute of Zagreb University, Faculty of Medicine (1969), Physiatric Institute of Sarajevo (1966), and other foreign institutions, usage of this mud is much more efficient in treatment of various rheumatic deseases and female genital deseases than the treatment in some other well known Adriatic treatment centres.
Trpanj's mud has some mechanic and chemical qualities putting it therefore into the group of therapeutic muds or so called peloids.
Over 22 tons of this mud that smells of hydrogen sulphide, can be enough for several hundred years of usage.
Blace lagoon is a natural resource, that could with a building of a facility be a prime-mover
of health tourism during whole year. Along with therapeutic qualities Blace has some other natural advantages:peace and beauty, mild climate with positive efect on the human organism for the purpose of treatment, rehabilitation and recreation. The great interest for this kind of therapy present in the world today gives great prospects for the development of health tourism in Trpanj.