You need to exchange euros when going to Portugal.

Euro is the currency of 19 countries in the European Union. The 19 member states of the euro are Germany, France, Italy, the Netherlands, Belgium, Luxembourg, Ireland, Spain, Portugal, Austria, Finland, Lithuania, Latvia, Estonia, Slovakia, Slovenia, Greece, Malta, and Cyprus. On January 1, 1999, a single monetary policy (Single Monetary Act) was implemented in EU countries that implemented the euro. In July 2002, the euro became the only legal currency in the euro area. The euro is managed by the European Central Bank (ECB) and the European System of Central Banks (ESCB), which consists of the central banks of the euro area countries. In addition, the euro is also the currency of 6 non-EU countries (regions): Monaco, San Marino, Vatican City, Andorra, Montenegro and Kosovo. Among them, the first four pocket countries use the euro according to their agreement with the EU, while the last two countries (regions) use the euro unilaterally.

Euro banknotes (pictured)*** are divided into 7 denominations of 5, 10, 20, 50, 100, 200 and 500 euros, with different sizes and colors. Each denomination of the banknote shows a European architectural period, a map of Europe and a European flag. For these seven denominations of banknotes, all of them adopt the design method of doors and windows on the front and a bridge on the back, which respectively show different architectural styles of different periods in Europe and represent seven different periods of European cultural history. The arches and window patterns symbolize the spirit of openness and cooperation, and the 12 stars of the European Union represent motivation and the unity of European countries. The bridge-shaped building on the back of the banknote represents cooperation and communication between European countries and between Europe and the world. The currency amount is printed on the banknotes, followed by Latin and Greek letters. The acronym of the European Central Bank is marked in five language variations of the official languages ??of the EU countries. The banknotes are printed with the flag and territory of the European Union, and the abbreviation of the European Central Bank is represented in five official languages ??used by the European Union, including BCE, ECB, EZB, EKT, and EKP, as well as the signature of the president of the central bank.