The Dark Matter @ LHC 2018 workshop will take place at the Kirchhoff-Institute for Physics in Heidelberg:
Im Neuenheimer Feld 227
69120 Heidelberg / Germany
Once at the building, follow the signs for "Dark Matter @ LHC 2018". The talks will be at lecture hall 1 (the big one).
... at #DMLHC2018.
Tel. +49 6221 98-54-9827
Tel. +49 6221 98-54-9800
A detailed map of the campus and the city including directions how to reach the Kirchhoff-Institute for Physics within Heidelberg by public transport is available from this link.
Heidelberg is a safe city and one can walk by foot after dark. If you want to get around a bit more, renting a bike may be a good idea.
Heidelberg is well connected through the railway: it is only 20 minutes away from Mannheim, a major hub on the north-south link in Germany and easily accessible within a few hours from many international connections like Geneva, Paris, Brussels, Amsterdam. The train station is 7 minutes away by tram 24 (usually every 10 minutes) from the Dark Matter @ LHC 2018 venue.
The closest international airport hubs are Frankfurt (FRA) with many international and intercontinental direct links and Stuttgart (STR). Both airports are well connected by rail and the travel time to Heidelberg is about 1 hour. At the airport, follow the signs for the railway and purchase a ticket to "Heidelberg Hauptbahnhof". C'est ça.