If you travel to exemple Sofia and they make a stop in Nis. Be sure how long they will stop there, so you dont miss the train. There is always someone who speaks little English or German. So, that means you will have time to buy some food and cold bevereages. On the train they just sell coffee and beer and water.
When we visited Nis in September 2009, one of the main city centre streets was under construction.
The street Vozda Karadorda which leads from the square Trg Kralja Milana to the east was more or less completely closed, so that we found it difficult to get to the Tourist Information Office, which can be found just behind the Hotel Ambassador.
For some reason someone had put a little bear next to the big construction site. I thought he was just a fabulous photo opportunity.