What to do when your bored?

ok me and my sis are at our grandparents house and me and my sister are bored and were in the middle of no where we cant drive cuz we're kids im 13 and shes 8 plz help and dont say color draw watch tv or paint or board games cuz we already did that and its retarded and we want to do something actually fun and extiting!!!!!!!!!!!!!!1 plz plz plz help