Svatojánský okruh
Accumulation of freshwater limestones
At the estuary of the karstic gorge, from the western and nothern side of the
church formed at the youngest time of Holocene (2700 – 8000 years ago) a big
accumulation of travertines (cold and freshwater requiring limestones). These
rocks precipitated, also under interaction of plants, from saturated karstic
waters, which bubbled out not far from limestone massif. The power of the
travertine cluster and completeness of the encountered geological profile are
unique, compared to similar outcrops in the republic and demonstrate character
and evolution of the natural environment and clime of the area in the youngest
history.
In freshwater limestones originated caves, where lived in the 9th century
legendary hermit Ivan. Later here was built a church and even later Benedictine
monastery. It is possible to go to the cave hermitage from the main area of the
church.
Waters, which gave rise to this phenomenon bubble out today in thw total amount
of 17 – 30 l/sec. and with almost permanent temperature 11,4°C from the
various places of traventine ensemble in the church, at the church garden and
even at the monastery’s boiler room whence is needed to drain them away. The
water was at the breakthrough of the 18th and 19th century drawned and selled as
curative.
In the environment of the groundwater lives here a miniature shellfish
bathynella natans (2 mm) which wa for the science for the first time discovered
in the Prague wells in the second half of the 19th century when aroused a big
splash in the scientific circles.
On the rock walls nests Eurasian Eagle-Owl (Bubo Bubo).
