There are at least three cathedrals in Oakland, in addition to the Cathedral of Learning, which is a cathedral metaphorically but not the seat of a bishop. Most Pittsburghers would be able to identify St. Paul’s, the Roman Catholic cathedral. Many would remember that there’s a Greek Orthodox cathedral, because its famous food festival attracts enough of a crowd to have an impact on Oakland traffic. This is the third. It was built as a Syrian Orthodox church in 1955, and it interprets traditional Eastern Christian forms with a sort of modernist severity.