Penn Wood - Visiting Woods - Woodland TrustPenn Wood is one of the largest ancient woodlands in the Chilterns Area of Outstanding Natural Beauty (AONB) and lies in the heart of this area.Size: 176.33 ha (435.71 acres) Grid reference: SU914959 Map reference: Explorer 172OS Landranger 165 Show location on Google Maps Penn Wood lies in the heart of the Chilterns Area of Outstanding Natural Beauty (AONB). It has a long history and was once https://www.woodlandtrust.org.uk/visiting-woods/wood/4812/penn-wood/