David- I contacted Norfolk and here are the location of two historic pieces of ordnance.

From Hampton Roads Naval Museum: I believe they are the two Brooke rifles that are sitting outside one of the buildings on the CFFC (ex-CINCLANT) compound. If I am not mistaken they are in front of the SURFLANT building. One is from CSS Albemarle and one is from CSS Tennessee. They are quite impressive. They are on loan to CFFC from the curator of the Navy.

David, this area is not part of Norfolk Naval Base. The guns are located down the road on Hampton Blvd.