Romania is by far the largest country in the Balkans, so it's no surprise that it contains a diverse range of landscapes and cultures. Although it's not as uniformly mountainous as several other Balkan countries, the beautiful Carpathian mountains cut right through the heart of the country and are an important part of its identity. The province of Transylvania, north and west of these mountains, is historically not part of the Balkans at all.
Romania's mountains provide many opportunities for hiking, from short walks to serious treks. Popular hiking areas have well-marked trails and plenty of cabanas. The Bucegi Mountains and Prahova Valley, south of Braşov, are particularly accessible, but there are many other possibilities.