Found this hole in the basement floor after moving the dryer. The dryer was standing on a piece of plywood covering the hole. It has a pipe connected to the cavity at about half of the depth, but the pipe seems to be completely clogged. I assume this is some emergency drain or something? It seems to have some remnants of old rubber sealing, but it is rotten. Almost all of the floor tile is original from the 1950s, but tiles near the hole seem to be replaced more recently. The pattern is a bit different.
I'm doing laminate floors all over the old floors. Should I keep this hole, seal it, or pour it with concrete?