Tufa towers are formed naturally when rain water in the surrounding mountains seeps into the ground, dissolving calcium from the rocks.
(Tufa towers; are formed naturally; T:when rain water in the surrounding mountains seeps into the ground, dissolving calcium from the rocks) (rain water in the surrounding mountains; seeps; into the ground)
Tufa towers rain water in the surrounding mountains
are formed naturally seeps
T:when rain water in the surrounding mountains seeps into the ground, dissolving calcium from the rocks
into the ground