Void filled with bricks underneath front garden?

[marty3]

Not sure if this is the right place for this, building might be more appropriate...

I am attempting to install a fence post in my front garden against a retaining wall. I have dug gown about half a metre and have uncovered a void filled with bricks.

Is this normal? I am assuming it is where they dumped all the old building materials when they built the front garden up.

I was planning on putting my fence post into the hole and then filling it with concrete. Anyone see an issue with doing that?

 

[JohnD]

I was thinking soakaway for your rainwater gutters, but I'm not so sure now. Did you make that hole? Can you poke a camera inside and take some flash pics?

How old is the house?

How close is the hole to the house?

Sometimes there's an old air-raid shelter.

 

[Mottie]

Or a plague pit!

 

[marty3]

House is 80s so doubt it will be a shelter, much to my dissapointment Will get a camera inside later on and post some pics