u/AdDependent8789

Looking for any info/date on this slag glass lamp. It is heavily stamped with “Harrison” on the inside of the panels. The bottom shows initials “HFW”. Can’t find any info online!

Does it need to be filled? Is it a well or something for septic? The rock covering it was not that large. It is empty and square shaped inside.

Was digging a hole to plant and hit a medium sized rock. Found this super deep hole, looks square shaped inside. Does it need to be filled or do I just cover it back up? Is it a well or something septic? Terrifying!