.375 AGW. This gold medal commemorates the centennial of the 1867 Treaty of London. This treaty, signed by all of the great powers in Europe, gauranteed Luxembourg's neutrality by removing fortifications and garrisoned troops thereby restoring personal freedom to the populace. Co-joined heads of Henri and Amelia of Luxembourg appear on the obverse. A gateway with "CENTENNIAL OF THE TREATY OF LONDON 1867-1967" appears on the reverse.