Extract from ''News Chronicle'', October 19 ....: ''RADIOACTIVE CITY'' OF LIGHT DARWIN, Wednesday. A Darwin explorer and photographer, Mr. Keith Young, believes he has found radioactivity in a mysterious ''forbidden city'' in Arnhem Land, inside the aboriginal reserve. Mr. Young went to photograph the ''city'' - which is fashioned by Nature from great limestone cliffs. The rock formation is shaped like battlements, towers, walls and streets. Mr. Young said: ''At night the "city" glowed with eerie light, which I consider to be radioactive in origin. ''He says he will not disclose the location of what he considers may be radioactive ores until he has discussed the matter with Canberra officials.-A. P.