There are many routes through the forests on the east and west sides of Stuttgart. Some have fitness stations along the way. You can stay on the level or go up and down the steep valley walls. Get a good map. There's some excellent beer gardens in the wood on the west side, and in the east side forest many Waldheim's where you can get good food.

You can run through the "Green U", a collection of parks that go on for about 6 miles with no street crossed at street level. That will take you from the Schlossplatz in the center of town, through the palace gardens, which is all flat, then starting uphill through Rosenstein Park and ending in Hoehenparkkillesberg on the ridge line. While there, climb up the architecturally interesting double helix tower for some excellent views over Stuttgart. You can also run around the routes in any of these parks.

Another good route would be to go through the palace gardens to the Neckar River (don't turn off through Rosenstein Park) and run on the foot/bicycle paths along the Neckar River on both sides in either direction, although I would recommend going North downstream because eventually you will also come to the large park at Max-Eyth-See (which you could also run around), and there is a foot bridge to cross to the other side of the river. By going North you can easily return on the U-14 which runs near the river to Remstal. This route would be level.

You could also run through the vineyards on the north side of town. For a very hilly workout, try the vineyards by Uhlbach, Untertuerkheim, Obertuerkheim and the Wuerttemberg Mausoleum on top of a high hill which held the castle which was their family seat. The grapes are ripening now so the vineyards are nice and the views good. If you go to the tourist information office across from the main train station on Koenigstrasse, you can get brochures on several vineyard routes and I'm sure the distances are all there on the accompanying maps. There is another pamphlet on vineyard routes around Bad Cannstatt, the Max-Eyth-See, and returning to Stuttgart along the valley sides. These brochures are for the Stuttgarter Weinwanderweg ( www.stuttgarter-weinwanderweg.de ).

You could also take the cable car up to the cemetary and run around up there. It's quite quiet and pleasant. The Blue Route which circles Stuttgart can also be accessed there.

If that's not enough for you, there are many Staeffele (stairways that connect the streets on the steep hillsides) which you can run up and down, or some small parks on the hillsides have switchbacking paths. A good map will show you hundreds of them. You could easily put together many interesting routes. It's no coincidence that the person holding the record for running up the Stuttgart TV tower and the Empire State Building is from Stuttgart.

A small mistake: "By going North you can easily return on the U-14 which runs near the river to Remstal."

That should be Remseck, not Remstal, but it would also be nice to run up the Rems Valley, the Rems River joins the Neckar at Remseck. I believe that there is also a bicycle route along it.

this is wonderful, thank you!

Do I need to pay to get in to the castle gardens if I'm just running there?

The palace gardens are open to anyone, there is no fee, as are all the places I mentioned. You should be able to do individual loops around the Upper, Middle and Lower Gardens, besides run between them. They're mainly grass and trees and a few ponds with ducks, geese and swans. Both Rosenstein Park and Hoehenparkkillesberg are quite large, so there are many possible routes, at least at Killesberg (you can use the U-7 to get there or return), but I'm not that familiar with Rosenstein Park as I'm usually on the other side of the fence at the zoo.

By the way, the two natural history museums are in Rosenstein park. Rosenstein Palace hosts a biology/ecology one, and at the other side of the park is Museum am Loewentor with its excellent collection of local dinosaurs, Ice Age mammals, all kinds of creatures embedded in amber, and the skull of 1/4 million years old Steinheim man.

Hoehenparkkillesberg, besides the excellent climbable tower has a very long miniature train ride (real steam engine on weekends), extensive flower beds including some nice dahlia ones, flamingoes, and some animals that would mainly appeal to children like llamas, goats, ponies, and sheep. It's a nice park.