@User9609 The grass will grow, but try not to leave to big bits of hardcore in there.
Here in college there is a big building project going on. There were archaeological digs on the main lawn. Basically when they built the 'new' chapel in 1800 and something, they dug a hole and put the old chapel in it. There are 2 small areas of lawn just off the main lawn that have always been a pain. The old chapel is in here too. They never grow lush.
The soil is always bone hard. We push garden forks in and wriggle them about for a 2 inch wide hole, sometimes we fill them with sand, yet still it remains compacted. I guess the soil has nowhere to go a the hardcore is there. (It's also a problem trying to get the forks in and out sometimes!)
If you just want green it'll probably be ok, if you want half decent I'd remove it.