The Tunnel of Eupalinos can be explored but it's not for the claustrophobic.
( ( ( ( ( ( The Tunnel ) ( of Eupalinos ) ) ( can ( be explored ) ) ) but ) ( it ( ( 's not ) ( for ( the claustrophobic ) ) ) ) ) . )
(ROOT (S (S (NP (NP (DT The) (NN Tunnel)) (PP (IN of) (NP (NNP Eupalinos)))) (VP (MD can) (VP (VB be) (VP (VBN explored))))) (CC but) (S (NP (PRP it)) (VP (VBZ 's) (RB not) (PP (IN for) (NP (DT the) (NN claustrophobic))))) (. .)))
The tunnel of Eupalinos is only one foot in diameter, barely large enough for a child to squeeze through.
( ( ( The tunnel ) ( of Eupalinos ) ) ( ( ( ( ( ( ( is only ) ( one foot ) ) ( in diameter ) ) , ) ( barely large ) ) ( enough ( for ( a ( child ( to ( squeeze through ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NN tunnel)) (PP (IN of) (NP (NNP Eupalinos)))) (VP (VBZ is) (ADVP (RB only)) (NP (CD one) (NN foot)) (PP (IN in) (NP (NN diameter))) (, ,) (ADJP (RB barely) (JJ large)) (ADVP (RB enough) (PP (IN for) (NP (DT a) (NN child) (S (VP (TO to) (VP (VB squeeze) (PRT (RP through))))))))) (. .)))