Franc
The Swiss franc (ISO code: CHF or 756), which appreciated significantly against the new European currency from April to September 2000, remains one of the world's strongest currencies, worth today around five-sixths of a euro. The Swiss franc is used in Switzerland and in Liechtenstein. Liechtenstein retains the ability to mint its own currency, the Liechtenstein franc, which it does from time to time for commemorative or emergency purposes.
Hard currency
The Swiss franc (CHF) has long been considered a hard currency, and in fact was the last paper currency in the world to terminate its convertibility to gold. In the summer of 2011, the European sovereign debt crisis led to rapid flows out of the euro and into the franc by those seeking hard currency, causing the latter to appreciate rapidly. On September 6, 2011, the Swiss National Bank announced that it would buy an "unlimited" number of euros to fix an exchange rate at 1.00 EUR = 1.20 CHF, to protect its trade. This action temporarily eliminated the franc's hard currency advantage over the euro but was abandoned in January 2015.