The Neustadt (New City) is a neighbourhood in Salzburg that was developed in the late 19th century on the site of the previously existing city walls and bastions. The 17th century fortifications took up a lot of space and had lost strategic importance. Therefore, they were demolished and the land was used to quickly develop a new residential and commercial area - similar to the story of the Ringstraße in Vienna.
Therefore, you find a similar Historicist style in the architecture of this area and various references to Austrian Imperial nobility - not for example the Franz-Josef-Straße. Similarly, the walls along the shores of the Salzach were removed and the river was being trained, resulting in the construction of lots of Gründerzeit/Historicist villas along the river. This includes parts of the Neustadt, note for example the buildings of the Schwarzsstraße (take the Christuskirche as a landmark), which also makes up one border of the Neustadt. One of the most important architects for the Neustadt was Jakob Ceconi.
Outlay & Sights of the Neustadt
Another reason for the quick development of the neighbourhood was probably the fire of 1818, which resulted in a great deal of destruction on this side of the river. At that point, Salzburg was in the midst of an economic and political crisis (it had just lost its independence a few years earlier and the salt trade contracted), the re-construction of buildings was slow and the materials in use rather cheap. This surely made it easier to replace them half a century later. Note for example the Andräkirche, which was originally the name of a Baroque church on the Platzl square. Heavily damaged in the fire, it was finally demolished and a new church was built at the heart of the Neustadt opposite Schloss Mirabell.
In the streets behind the Andräkirche, you find rather large Historicist "Mietshäuser” (rental houses) of the Neustadt which provided residential space and room for shops and businesses. The style is very Viennese and doesn′t really go well with Salzburg at all; back then, people were apparently not very sensitive about this - only in the later 20th century, at least the enormous and pompous Andräkirche was decreased in size and pomposity.
Hidden Treasures of Salzburg
German Wikipedia on the Neustadt
Salzburg Wiki in German on Jakob Ceconi
City of Salzburg, Official Website