I fell into a giant ocean hole at my grandparents house

Date: 8/31/2019

So this dream is short compared to my others and it happened a while ago... But anyway I was at my grandparents house in their backyard. They have a pretty big backyard...enough to fit a big playhouse, swing set, and a croquet court. Well I was standing in the middle of the yard (I was in the 3rd person so I could see myself). All of a sudden... This GIANT HOLE opened up in the middle of the yard. Out of nowhere. It was probably 30 feet wide. I was like what the actual hell?! What was even scarier was the fact that it was filled with ocean water and a bunch of sea creatures. Sting rays, sharks, whales, you name it. It was in that hole. Of course, I fell into it. Luckily my dream ended before I could get eaten by a shark or stung by a stingray or something.