777 City Park Ave

The house has an abnormal amount of video and data runs.
 
One day when following some back, I found I small hidden room behind some shelves, that I assumed to be a root cellar. We jokingly call it the 'safe room'.  I've used it to store gardening stuff over the winter.  Using it to force flowers to hibernate over the winter.  Previously I noticed what looked like a man hole cover in the floor.

I pretty much left it alone, assuming that it went to the sewer and that unsealing it might lead to something unpleasant.  But today curiosity got the better of me.
I tried pulling up on it but it wouldn't budge.
I took a crowbar to it and opened it.

There is a hole in the floor that opens up after about 3 feet.

Below is a perfectly round room with completely smooth walls.
The room has about an 8 foot diameter and goes about 15 feet down.
It's a really big room.


Of to the side is a small tunnel that goes as far as I can see.

I would have climbed down, but I could not see a way to get out.  This is a good distance below the basement floor.  The walls look like they were made with Very large stones and have almost no seams.  Plus I'm pretty sure I wouldn't have good cell phone reception down there.  I'm going to get some of my climbing friends and repel down there.

This house keeps serving up surprise after surprise.