Mayor King praised the city of Ypres and the special bond between them and Hamilton.
"[The memorial] will be a symbol of friendship and goodwill between the two cities," King said.
Minister of Veterans' Affairs and MP for Hamilton East David Bennett was also in attendance, along with several Hamilton City Councillors and other MPs.
Bennett thanked the Hamilton mayor for his support of the project while also praising Bos, who had been the catalyst for a number of remembrance events.
The minister stated that the memorial will serve as a fitting tribute to those who sacrificed their lives in Belgium.
"This memorial is a place to remember the freedom that we have today that those soldiers fought for," Bennett said.
"Hamilton should be proud to have this garden."
As two army cadets held the flags of both New Zealand and Belgium, Bennett, King, Victoria Cross recipient Corporal Willie Apiata and Bos unveiled the plaques.
The plaques read "Honouring our sacrifice daily" and "We both gave so much" accompanied by the musical notes of The Last Post etched into the plaque.
The bugle call was played to those in attendances, where just under 19,000km away, the same call is played every night at 8pm at the Menen gates in the town of Ypres.