Two natural rock formations are always pointed out on excursions.
( ( Two ( natural ( rock formations ) ) ) ( ( ( are always ) ( ( pointed out ) ( on excursions ) ) ) . ) )
(ROOT (S (NP (CD Two) (JJ natural) (NN rock) (NNS formations)) (VP (VBP are) (ADVP (RB always)) (VP (VBN pointed) (PRT (RP out)) (PP (IN on) (NP (NNS excursions))))) (. .)))
There is only one natural rock formation in the area.
( There ( ( ( is only ) ( ( one ( natural ( rock formation ) ) ) ( in ( the area ) ) ) ) . ) )
(ROOT (S (NP (EX There)) (VP (VBZ is) (ADVP (RB only)) (NP (NP (CD one) (JJ natural) (NN rock) (NN formation)) (PP (IN in) (NP (DT the) (NN area))))) (. .)))