Bell Lane (the Hertfordshire Way) has doable parking or Millhouse Lane is more secluded (and a possible dash and cache). You're looking for a 10cm by 3cm tube with a few odds and ends, a pencil and notebook for a log. If you fancy a walk after finding it, try going to Millhouse Lane, turn right down the road and a walk across the fields.
In late April/May you'll find a carpet of bluebells nearby.
Evtug ng tebhaq yriry.