Does anyone have this fear?

I have always been nervous around certain huge manmade things. The main things that make me extremely uncomfortable are ships and large dams. I was fishing with my dad and he went next to the saddle dam of a lake in a boat. This happened when I was teenager. This isn’t the main dam and boats are permitted next to it. It was an embankment (earthen) dam that had rip rap (rocks to prevent erosion) going all the way up the the entire side of the dam facing the lake. It was enormous. well over 200 feet high and it overtook my entire feild of vision. It didn’t look as big from afar but that close it was so huge that I felt extremely uncomfortable and scared. It was silly because I was reletively safe as long as I didn’t fall into the water. Why was I so scared of an inanimate yet enormouse object. I still go to that lake. I can drive on top of dams the same size and not be scared at all but in the boat on the water I felt extremely intimidated. Is this normal