Onsala, general map (link to eniro.se)
The Group for advanced receiver develoopment, GARD, is not located in Onsala but at Chalmers Campus Johanneberg in Gothenburg, in the same building as the Department of microtechnology and nanoscience, MC2:
The observatory area with restricted access (information and map).
Map of the observatory area:
The map above with better resolution: Map ObservatoryArea.pdf