Bosnia and Herzeggovina sometimes called Bosnia-Herzegovina or simply Bosnia, is a country in Southeastern Europe, on the Balkan Peninsula. Its capital and largest city is Sarajevo with an estimated urban population of 430,000 people. Bordered by Croatia to the north, west and south, Serbia to the east, and Montenegro to the southeast, Bosnia and Herzegovina is almost landlocked, except for the 20 kilometres (12 miles) of coastline on the Adriatic Sea surrounding the city of Neum. In the central and southern interior of the country the geography is mountainous, in the northwest it is moderately hilly, and the northeast is predominantly flatland. The inland is a geographically larger region and has a moderate continental climate, bookended by hot summers and cold and snowy winters. The southern tip of the country has a Mediterranean climate and plain topography
The first preserved mention of the name "Bosnia" is in De Administrando Imperio, a politico-geographical handbook written by theByzantine emperor Constantine VII in the mid-10th century (between 948 and 952) describing the "small country" (χωρίον in Greek) of "Bosona" (Βοσώνα). The Chronicle of the Priest of Duklja from 1172-1196 of Bar's Roman Catholic Christian Archbishop names Bosnia, and references an earlier source from the year of 753 - the De Regno Sclavorum (Of the Realm of Slavs). The name "Bosnia" probably comes from the name of the Bosna river around which it has been historically based, which was recorded in the Roman eraunder the name Bossina. More direct roots of the river's names are unknown. Philologist Anton Mayer proposed a connection with the Indo-European root *bos or *bogh, meaning "running water". Certain Roman sources similarly mention Bathinus flumen as a name of the Illyrian Bosona, both of which would mean "flowing water" as well. Other theories involve the rare Latin term Bosina, meaning boundary, and possible Slavic origins.