▁" M am alu ", ▁meaning ▁" Sh ady ▁La wn s ." ▁The ▁Walk ers ▁turned ▁the ▁estate ▁into ▁world - f am ous ▁orch id ▁gard ens . ▁ ▁On ▁April ▁ 2 4 , ▁ 1 9 7 3 , ▁at ▁the ▁request ▁of ▁Una ▁Walker , ▁H . ▁Alexander ▁Walker ' s ▁wid ow , ▁the ▁house ▁was ▁added ▁as ▁site ▁ 7 3 0 0 0 6 6 5 ▁to ▁the ▁National ▁Register ▁of ▁Historic ▁Places ▁list ings ▁in ▁O ahu ▁and ▁listed ▁as ▁a ▁" valu able ▁historic ▁property " ▁by ▁Hawai i ▁Historic ▁Places . ▁Una ▁Walker ▁maintained ▁the ▁estate ▁by ▁making ▁the ▁grounds ▁available ▁for ▁wed d ings ▁and ▁visitors ▁and ▁as ▁a ▁movie ▁and ▁television ▁set . ▁ ▁It ▁appeared ▁in ▁many ▁Hawai i ▁ 5 - 0 ▁and ▁Mag num ▁P I ▁shows . ▁Una ' s ▁grand son , ▁former ▁Hawai i ▁Att orney ▁General ▁Michael ▁A . ▁L illy ▁and ▁his ▁wife ▁C ind y ▁Walter ▁were ▁the ▁last ▁members ▁of ▁the ▁Walker ▁family ▁to ▁live ▁on ▁the ▁estate . ▁In ▁ 1 9 8 9 , ▁two ▁years ▁after ▁Una ' s ▁death , ▁the ▁house ▁and ▁its ▁ ▁grounds ▁were ▁sold ▁by ▁the ▁Walker ▁he irs ▁to ▁Mas ao ▁N ang aku ▁of ▁Min ami ▁Group ▁( USA ) ▁Inc . ▁for ▁$ 8 . 5 ▁million . ▁His ▁intention ▁was ▁to ▁restore ▁the ▁original ▁house ▁to ▁be ▁used ▁as ▁a ▁corpor ate ▁retre at . ▁He ▁renov ated