Darmstadt is about 30 mins. by train from Frankfurt. Once in the town follow the home fans onto trams to the ground. We found a decent brewpub not far from the station which welcomed away fans and had friendly clientele who bought us a round of drinks.

Once at the stadium the 3 new stands appear to have been dropped into the old, open bowl of the ground. So one side is completely uncovered and I watched the away fans getting soaked during a downpour that lasted the length of the game. We were dry in the end but the stand has a temporary feel to it and you have to go outside to get a beer or use the portaloos. So basically everyone who was drinking got soaked too.