Within the city limits of Vienna, there is a large 6 km² park / nature reserve of called the Praterwald (Prater Forest). It is a swampy forested flood plain of the Danube River. However, since the 1800's it has been cut off from the river when a major engineering project completed in 1870, straightened the river.
It was long used by the Austrian Emperors as a hunting ground, but in 1873 it was the site for the World Fair.
Today it is used a large recreational park by may of Vienna's residents.
If you know what you're looking for, the Praterwald is a wealth of edible plants and herbs.
Stinging Nettles can be used as a curative herb, or cooked like spinach. It has a far higher iron content than the later. The fibres in the stems can also be used to make string. It is an incredibly useful plant, although most people treat it as a weed.
Wild garlic brings people to the forest in Spring. From it's leaves you can make delicious pesto or other dishes. As the name suggests, it smells and tastes like garlic.
Wild Garlic is typically found in damp woodland areas. It is usually taken as a sign that the woodland is in good health.
It is one of the first plants to grow again in early Spring. It takes advantage of the trees not yet having leaves, with the forest floor being flooded with light.
Once the trees start to bud and grow leaves and start shading out the Wild Garlic, it starts to flower. By the end of Spring it has seeded and "died off" with the bulbs waiting patiently in the ground until the next Spring.
The Prater is dotted with many meadows. Where there are meadows, you'll find dandelions. These are an essential food source for many animals, but are also edible for humans.
The reeds of the wetlands provide an important habitat for many animals. During spring, many water fowl are nesting amongst them. You'll hear the frogs incessantly croaking as well.
The reeds also used to be an important building material, used for roofing and insulation.
There are many paths that weave through the Prater, where you can discover a quiet green corner to escape the nearby city. Not only is it a refuge for wildlife, but also for the local residents.