Crankcase Plug size on 97 Disco

[Doss]

Well I was getting ready for my first oil change in my Disco. I crawled under with tool box in hand to remove the plug. I was amazed that I didn't have a socket big enough. I have a 1" socket and it was still too small (obviously it will be metric) but I was getting a feel for it.
What size do I need?

Thanks

 

[Moose]

27mm or 1 1/16"

Or use a crescent wrench