"They actually tied a knot. They tied a fisherman’s knot and it’s the strongest knot. The rope will break before the knot comes undone and the knot only gets tighter with pressure." Frame knot and vows as a keepsake.
I love this idea: Write love letters to each other and add a bottle of wine into a box and nail it shut at the wedding. You aren't supposed to open it until your 25th wedding anniversary. Unbelievably romantic <3