I'm not quite sure how to describe this phenomena but in my town we have a large boardwalk structure and it is closed off almost entirely underneath by a sea wall. this leaves slits on top with the boards and slits near the top of the sea wall where a concrete beam will pass through. at certain times of the day i have observed circular dots of sunlight on the ground underneath it accompanied by the expected slits of light from the boards but there are no circular openings anywhere on the structure. they are scattered in strange patterns often forming clear interference patterns if in the correct location. on multiple occasions i have placed my hand underneath them and lifted to find the source. but to my dismay the light often curves in impossible directions while maintaining its dot like shape. if i manage to isolate the dot at eye level i can often look and find the source and find myself staring directly into the sun nowhere near where it was located. if anyone has any idea what this is i can go out and get pictures as it occurs around this time of the day.