1 9 7 1 . ▁. ▁ ▁Second ▁re vised ▁and ▁updated ▁edition ▁published ▁ 1 9 9 5 ▁by ▁C ré cy ▁Publishing , ▁. ▁ ▁Th ir sk , ▁Ian . de ▁Hav ill and ▁Mos qu ito : ▁An ▁Illustr ated ▁History ▁Volume ▁ 2 . ▁Manchester : ▁C ré cy ▁Publishing , ▁ 2 0 0 6 . ▁. ▁ ▁De ▁Hav ill and ▁Mos qu ito ▁de ▁Hav ill and ▁Mos qu ito ▁Oper ators <0x0A> </s> ▁F an ▁B w l ch ▁Ch w yth ▁is ▁a ▁peak ▁in ▁the ▁F for est ▁F aw r ▁section ▁of ▁the ▁Bre con ▁Be a cons ▁National ▁Park ▁and ▁within ▁the ▁county ▁of ▁Pow ys . ▁ ▁Its ▁sum mit ▁( at ▁ 6 0 3 ▁m ) ▁is ▁marked ▁by ▁a ▁trig ▁point ▁at ▁OS ▁grid ▁ref ▁SN ▁ 9 1 2 2 1 7 . ▁ ▁Ge ology ▁ ▁The ▁hill ▁is ▁formed ▁from ▁sand st ones ▁and ▁mud st ones ▁of ▁the ▁Sen ni ▁B eds ▁Form ation ▁and ▁Brown st ones ▁Form ation ▁of ▁the ▁Old ▁Red ▁Sand stone ▁laid ▁down ▁during ▁the ▁Dev onian ▁period . ▁A ▁north - n orth west ▁- ▁south - s out heast ▁tr ending ▁fault ▁runs ▁across ▁its ▁north - e astern ▁face . ▁ ▁This ▁face ▁is ▁much ▁the ▁ste ep est ▁and ▁has ▁its ▁orig ins ▁in ▁the ▁ice ▁ages ▁when ▁a ▁minor ▁gla cier ▁grew ▁at ▁this ▁spot . ▁ ▁It ▁has ▁left ▁a ▁couple