It is housed in a Martello A series of such towers, some 12 m (40 ft) high and 2.5 m (8 ft) thick, were constructed along the coast at the beginning of the 19th century to guard against invasion by Napoleon.
( ( It ( is ( housed ( in ( ( a ( Martello ( A series ) ) ) ( of ( such towers ) ) ) ) ) ) ) ( , ( ( ( ( ( ( some ( ( 12 m ) ( ( -LRB- ( ( 40 ft ) -RRB- ) ) high ) ) ) and ) ( 2.5 ( m ( -LRB- ( ( 8 ft ) -RRB- ) ) ) ) ) thick ) , ) ( ( were ( ( constructed ( along ( ( the coast ) ( at ( ( the beginning ) ( of ( the ( 19th century ) ) ) ) ) ) ) ) ( to ( ( guard ( against invasion ) ) ( by Napoleon ) ) ) ) ) . ) ) ) )
(ROOT (S (S (NP (PRP It)) (VP (VBZ is) (VP (VBN housed) (PP (IN in) (NP (NP (DT a) (NNP Martello) (NNP A) (NN series)) (PP (IN of) (NP (JJ such) (NNS towers)))))))) (, ,) (NP (NP (DT some) (ADJP (CD 12) (JJ m)) (PRN (-LRB- -LRB-) (NP (QP (CD 40) (CD ft))) (-RRB- -RRB-)) (NN high)) (CC and) (NP (CD 2.5) (NN m) (PRN (-LRB- -LRB-) (NP (QP (CD 8) (CD ft))) (-RRB- -RRB-))) (ADJP (JJ thick)) (, ,)) (VP (VBD were) (VP (VBN constructed) (PP (IN along) (NP (NP (DT the) (NN coast)) (PP (IN at) (NP (NP (DT the) (NN beginning)) (PP (IN of) (NP (DT the) (JJ 19th) (NN century))))))) (S (VP (TO to) (VP (VB guard) (PP (IN against) (NP (NN invasion))) (PP (IN by) (NP (NNP Napoleon)))))))) (. .)))
The largest tower built along the coast was 30 feet high and 6 feet thick.
( ( ( The ( largest tower ) ) ( built ( along ( the coast ) ) ) ) ( ( was ( ( ( ( 30 feet ) high ) and ) ( ( 6 feet ) thick ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (JJS largest) (NN tower)) (VP (VBN built) (PP (IN along) (NP (DT the) (NN coast))))) (VP (VBD was) (ADJP (ADJP (NP (CD 30) (NNS feet)) (JJ high)) (CC and) (ADJP (NP (CD 6) (NNS feet)) (JJ thick)))) (. .)))