The number of steps built down into the interior means that it is unsuitable for the infirm or those with heart problems.
( ( ( The number ) ( of ( steps ( ( built down ) ( into ( the interior ) ) ) ) ) ) ( ( means ( that ( it ( ( is ( unsuitable ( for ( ( ( the infirm ) or ) those ) ) ) ) ( with ( heart problems ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NN number)) (PP (IN of) (NP (NP (NNS steps)) (VP (VBN built) (PRT (RP down)) (PP (IN into) (NP (DT the) (NN interior))))))) (VP (VBZ means) (SBAR (IN that) (S (NP (PRP it)) (VP (VBZ is) (ADJP (JJ unsuitable) (PP (IN for) (NP (NP (DT the) (NN infirm)) (CC or) (NP (DT those))))) (PP (IN with) (NP (NN heart) (NNS problems))))))) (. .)))
There are a hundred steps leading into the interior.
( There ( ( are ( ( a ( hundred steps ) ) ( leading ( into ( the interior ) ) ) ) ) . ) )
(ROOT (S (NP (EX There)) (VP (VBP are) (NP (NP (DT a) (CD hundred) (NNS steps)) (VP (VBG leading) (PP (IN into) (NP (DT the) (NN interior)))))) (. .)))