Myeongdong Cathedral
The Cathedral Church of Virgin Mary of the Immaculate Conception ( ; ) , informally known as Myeongdong Cathedral , is the national cathedral of the Roman Catholic Archdiocese of Seoul . 
<triplet> Myeongdong Cathedral <subj> cathedral <obj> instance of <subj> Roman Catholic Archdiocese of Seoul <obj> diocese <triplet> Roman Catholic Archdiocese of Seoul <subj> Myeongdong Cathedral <obj> cathedral