Grobiņa is a suburb of Liepāja, accessible by city bus.
It has the Liepāja’s agglomeration sole surviving Medieval castle, built in 1253 by the Order of Livonian Knights. It is relatively small and now ruined, but can be picturesque.
Grobiņa is also famous for its Viking-era graves of Scandinavians who disembarked on Baltic’s Eastern shore. One would have to be interested in prehistory and archaeology to be able to enjoy them however.