Visit any Graveyard for your Grandparents please.
For the faithful departed
§ 1. A plenary indulgence, applied exclusively to the souls in Purgatory, is granted to the Christian faithful who:
1° on each single day, from the first to the eighth day in November, devoutly visit a cemetery and, even if only mentally, pray for the faithful departed; [Note: one plenary indulgence for each day, if the usual conditions are met]
2° on the day of Commemoration of All Faithful Departed [November 2] (or, according to the Ordinary, on the preceding or subsequent Sunday, or on the day of the solemnity of All Saints) piously visit a church or oratory and there recite the Pater and the Credo.