( ( In ( ( the middle ) ( of ( the temple ) ) ) ) ( , ( ( beyond ( this wall ) ) ( ( used ( to ( be ( ( a ( large ( concave lens ) ) ) ( lined ( with gold ) ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN In) (NP (NP (DT the) (NN middle)) (PP (IN of) (NP (DT the) (NN temple))))) (, ,) (NP (IN beyond) (DT this) (NN wall)) (VP (VBD used) (S (VP (TO to) (VP (VB be) (NP (NP (DT a) (JJ large) (NN concave) (NN lens)) (VP (VBN lined) (PP (IN with) (NP (NN gold))))))))) (. .)))
In the middle of the temple, beyond this wall used to be a large concave lens lined with gold.
(ROOT (S (NP (DT A) (JJ concave) (NN lens)) (VP (VBZ is) (NP (NP (JJR thicker)) (PP (IN at) (NP (DT the) (NNS edges)))) (SBAR (IN than) (S (NP (PRP it)) (VP (VBZ is) (PP (IN in) (NP (DT the) (NN middle))))))) (. .)))
A concave lens is thicker at the edges than it is in the middle.