A visit to a shrine, temple, or grave to pray or pay respects; an act of worship or visiting (related to the verb 参る/参拝).
週末にお墓参りに行き、親の供養をした。
I went to visit my parents' graves over the weekend and held a memorial.
初詣で神社にお参りした。
I visited the shrine for hatsumode (New Year's visit).
お参りする前に手を清めてください。
Please wash your hands before praying/visiting (the shrine).