au, at the foot of which there probably used to be a trench. Over
this a bridge led to the gate of the second plateau. The trench has been
long since filled in, but the huge round tower which guarded the gate
still remains and is the Vestner Thurm. The Vestner Thurm of Sinwel
Thurm (sinwel = round), or, as it is called in a charter of the year
1313, the "Middle Tower," is the only round tower of the Burg. It was
built in the days of early Gothic, with a sloping base, and of roughly
flattened stones with a smooth edge. It was partly restored and altered
in 1561, when it was made a few feet higher and its round roof was
added. It is worth paying the small gratuity required for ascending to
the top. The view obtained of the city below is magnificent. The Vestner
Thurm, like the whole Imperial castle, passed at length into the care of
the town, which kept its Tower watch here as early as the fourteenth
century.

The well which supplied the second plateau with water, the "Deep Well,"
as it is called, stands in the center, surrounded by a wall. It is 335
feet deep, hewn out of the solid rock, and is said to have been wrought
by the hands of prisoners, and to have been the labor of thirty years.
So much we can easily believe as we lean over and count the six seconds
that elapse between the time when an object is dropt from the top to the
time when it strikes the water beneath. Passages lead from the water's
edge to the Rathaus, by which prisoners came formerly to draw water, and
to St. John's Churchyard and other points outside the town. The system
of underground passages here and in the Castle was an important part of
the defenses, affording as it did a means of communication with the
outer world and as a last extremity, in the case of a siege, a means of
escape.

Meanwhile, leaving the Deep Well and passing some insignificant modern
dwellings, and leaving beneath us on the left the Himmelsthor, let us
approach the summit of the rock and the buildings of the Kaiserburg
itself. As we advance to the gateway with the intention of ringing the
bell for the castellan, we notice on the left the Double Chapel,
attaching to the Heathen Tower, the lower part of which is encrusted
with what were once supposed to be Pagan images. The Tower protrudes
beyond the face of the third plateau, and its prominence may indicate
the width of a trench, now filled in, which was once dug outside the
enclosing wall of the summit of the rock. The whole