For anyone looking for a bit more variety of flora, fauna, geology/landscape and space, you could do a lot worse than Chopwell Wood. Obviously not quite on the doorstep but only about 25-30 mins drive from Sunderland. No FC Rangers to worry about any more ( apparently its only worth checking once a month), the only thing to watch out for is bikes but you can "lose yourself" very easily in the wood if you wish to do so. Anyone actually "lost" in the wood, really just needs to look for the power lines and follow them or the forest tracks uphill till you hit the tarmac road, the car park or the old railway line, then follow the signs.
Good luck and if you do fancy a look around Chopwell, I might even join you to show you around sometime.
Steve