Bulgaria and the euro numerals). However, the word stotinki (стотинки), singular stotinka (стотинка), the name of the subunit of the current Bulgarian currency, could be used in place of cent, as it has become a synonym of the word "coins" in colloquial Bulgarian; just like "cent" (from Latin centum), its etymology is from a word meaning hundred – "sto" (сто). Stotinki is used widely in the Bulgarian diaspora in Europe to refer to subunits of currencies other than the Bulgarian lev. Bulgaria and the euro Bulgaria committed to switching its currency, the lev, to the euro upon its joining the European Union in 2007,
Tourism in Bulgaria are around 4,500 discovered underground formations in Bulgaria. The earliest written records about the caves in Bulgaria are found in the manuscripts of the 17th century Bulgarian National Revival figure and historian Petar Bogdan. The first Bulgarian speleological society was established in 1929. The caves in the country are inhabited by more than 700 invertebrate species and 32 of the 37 species of bats found in Europe. Most visitors arriving in Bulgaria on short-term basis came from the following countries of nationality: Tourism in Bulgaria Tourism in Bulgaria is a significant contributor to the country's economy. Situated at the crossroads