As the scope and ambitions of the Burggrafs increased, and as the smallness of their castle at Nuremberg, and the constant friction with the townspeople, who were able to annoy them in many ways, became more irksome, they gave up living at Nuremberg, and finally were content to sell their rights and possessions there to the town. Beside the guard door of the Burggrafs, which together with their castle passed by purchase into the hands of the town (1427), there were various other similar guard towers, such as the one which formerly occupied the present site of the Luginsland, or the Hasenburg at the so-called Himmels Thor, or a third which once stood near the Deep Well on the second plateau of the Castle rock. But we do not know how many of these there were, or where they stood, much less at what date they were built. All we do know is that they, as well as the Burggrafs' possessions, were purchased in succession by the town, into whose hands by degrees came the whole property of the Castle rock. Above the ruins of the "little fort" of the Burggrafs rises the first plateau of the Castle rock. It is surrounded by a wall, strengthened on the south side by a square tower against which leans the Walpurgiskapelle. The path to the Kaiserburg leads under the wall of the plateau, and is entirely commanded by it and by the quadrangular tower, the lower part of which alone remains and is known by the name of Burgamtmannswohnung. The path goes straight to this tower, and at the foot of it is the entrance to the first plateau. Then along the edge of this plateau the way winds southward, entirely commanded again by the wall of the second plateau, 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.