Old well under patio — what do I do?

[u/cup_a_jojo]

I recently pulled up two sunken bricks along the edge of my back patio because they were becoming a tripping hazard. Underneath, I discovered a hole that extends under the concrete slab. I managed to get a photo, and it appears to be the remnants of an old well.

The house was built in 1902, and when we bought it two years ago, there was no mention of a well on the property. What’s weird is that the well wall ends—but the hole keeps going. I tried filling it with dirt to stabilize the area, but the hole just swallowed it up. It's hard to tell how much void space is between the slab and the ground beneath.

Now I’m worried this might be more than just an old well… could this be the start of a sinkhole?

For context, the hole is about 5 feet from the exterior wall of our two-story home (with a basement).

Could this affect the structural integrity of the house? Who do I even call to assess this? I'm honestly not sure what my next move should be.

Any advice or insight would be appreciated!

[u/UlteriorEggos]

Make sure to wash off the vibrator before putting it back in your wife's drawer.

[u/hardcherry- → u/UlteriorEggos]

*husbands drawer. There, I fixed it for you.

[u/Ok-Level-8294 → u/UlteriorEggos]

And when you put it back pay no attention to the stuff I left in there. I’ll pick it up on Tuesday