The Caldes de Malavella municipality has some very special geological characteristics: it is situated on a set of faults that extend over a large part of Europe and that produced a series of volcanic eruptions on our territory.
The Camp dels Ninots volcano is called maar. In the case of the Camp dels Ninots maar, most of its structure is below earth, and on the surface only some small, very gentle and low elevations can be seen. It has an irregular, slightly elliptical surface that has a maximum axis of 2,133 feet in a northeast-southeast direction; one minimum, perpendicular to the previous one, of 1,394 feet, and a height, according to sea level, of 305 feet.