SCENERY OF SWITZERLAND. 
130 
Fig. 1 15 shows the folds of the strata, which, if the 
light suits, may be clearly made out from the valley. 
Above Martigny one sees clearly the contact of 
the Calcareous and Crystalline 
rocks on the north of the valley 
gradually descending towards 
Saillon. Sion owes its picturesque 
and feudal aspect, and indeed, 
its importance in mediaeval times, 
to the fact that the river has left 
several masses of native rock, on 
which three castles were built. 
The highest was formerly the 
Bishop’s Palace, built in 1492, 
but now a ruin. Just above Sion 
the Borgne has formed a fine 
cone, and driven the Rhone to 
the foot of the opposite moun- 
tain. 
At and round Sierre are great 
mounds which look very like re- 
mains of a moraine, but are 
generally regarded as a rockfall, 
which in that case must have 
been the most gigantic in the 
whole of Switzerland, excepting 
