Anyway, doing some tetrad work late morning I came across a WOOD WARBLER in Brocket Park. The bird was generally very elusive and singing only very occasionally, but it did show well once or twice. The bird was observed on 3 occasions between 11.55 and 12.15 when I left.
Take Marford Rd between WGC and Wheathampstead, and park in the main layby on the Brocket side of the road. Follow the footpath down through the woods, cross river Lea and turn right up the steep wooded bank into what is known as Bluebell Wood (very original!!). The bird was in the wooded area at the top of the hill. Stick to the footpath - that was the area where it was singing from anyway (Anthony Dorman)