Waterloo and how to "leave" the euro

Belgium commemorates waterloo with a €2.50 coin. "The coins, which can only be spent inside Belgium, display a monument of a lion atop a cone-shaped hill on the site of France’s humiliation, as well as lines indicating where troops were positioned when forces led by Britain and Prussia defeated Napoleon in the countryside near Brussels."

As a corollary, does this mean that Greece can "exit" the euro by minting a bunch of 7, 11, 34 euro coins?

Source: http://www.nytimes.com/2015/06/10/world/eu...