Stadtpark - green space by yooperprof
The Stadtpark is a lovely "nature-space," lying just outside the Sudbahnhof amidst rolling hills and lush plantings. Even in January, things were in bloom here - admittedly, it was quite a warm Janaury, but I can understand why soldiers from Rome two thousand years ago might have liked it here.
It's located between the Altstadt and Oberstadt neighborhoods.