The Van Helsing Caravan was Eric and Jonathan's home in Stokely. That and their secret Slayer HQ are assumed to be their most important locations. Mina lived there for a while whilst trying to make her husband and son stop believing in vampires.
What happened to the caravan following the fall of Stokely is unknown as the Van Helsings have set off in pursuit of the Dracula family and Eric is deceased.