Mr Mulhall served in the Royal New Zealand Navy and was one of 30 New Zealand army and navy veterans who returned to mark the Korean Armistice last month.
He was posted to Korea in 1957 as an engineer on the cruiser HMNZS Royalist, conducting patrols in the post-war period.
He said the buildings and the tight security on the South Korea-North Korea border was what struck him the most.
''You used to be able to walk in from the South, but now there's guards on the doors. You can't take any photos of these guards.
''You could see the guards watching us from the North. It's a very eerie set up.''
Like many of the 30 delegates, it was his first visit to the country since he served there.
The New Zealand delegation was taken by a Royal New Zealand Air Force plane and Mr Mulhall said the week was a real privilege.
The delegates spent most of the week in Seoul, the South Korean capital.
''It's amazing how the country has developed. It has a very strict routine and it's a very touchy area.''
Mr Mulhall said the trip was unexpected, as he had put his name in a ballot and was one of the lucky ones to be picked.
Representatives from all over the world were present at the Armistice Day celebrations.
''It was all the old guys together.''
''It was a once-in-a-life-time-experience.''
TS Waireka Sea Cadets member James Edie (20), of Dunedin, was also one of the 30 delegates.
Under Officer Edie (20) was nominated to represent the New Zealand Cadet Forces after receiving a Warrant Officer Defence Force medallion for leadership.
