Vihren is situated in the northern subdivision of Pirin on the mountain's main ridge between the summits of Kutelo (2,908 m) to the north-west and Hvoynati Vrah (2,635 m) to the south-east.^[4] It is connected with these two peaks via the saddles of Premkata (2,610 m) to the north and Kabata (2,535 m) to the south.^[4] The summit is located between the valleys of the rivers Vlahina reka of the Struma drainage to the west and Banderitsa of the Mesta drainage to the east.^[2]

Seen from the town of Bansko, situated at the foothills of Pirin to the north-east of Vihren, the peak looks like a truncated pyramid, and from the south — like а tetrahedral pyramid.^[4] The summit is built up marbles^[4] and has a karst topography which determines the lack of streams and lakes around Vihren. The closest lakes are the Vlahini Lakes to the south-west.^[4] To the north are situated the deep and waterless cirques Golemiya Kazan and Malkiya Kazan, known as the Kazanite (the cauldrons).^[4] Below the 450 m-high walls of Vihren facing Golemiya Kazan there is a small glacier called Snezhnika, which is Europe's southernmost glacial mass.^[3][7] Its size in summer is 80x90 m.^[8]

The average annual minimal temperature varies between –25° and –21°С, while the maximal temperatures are between 15° and 23°С. The mean annual precipitation is 1150 mm; the snow cover reaches depth of 3 m.^[6] There is a meteorological station at 1,950 m.^[6]

The wildlife is alpine. The flora of Vihren's slopes consists of herbaceous plants and lichens.^[6] Vihren is home to a number of habitats, including alpine and sub-alpine open calcareous grasslands that at inclination of 30–45° at altitude over 2,500 m on the marble bedrock forms phytocenosis dominated by Sesleria korabensis,^[9] and alpine and sub-alpine closed calcareous grasslands on very rocky bedrock.^[10] With less abundance is the relict plant Carex rupestris; some plant communities have an abundance of Carex kitaibeliana and Sesleria coerulans.^[9] There are also Alyssum cuneifolium, Bellardiochloa variegata, Bromus lacmonicus, Cerastium lanatum, Koeleria eriostachya, Onobrychis pindicola, Scutellaria alpina, Sesleria coerulans, etc.^[10] Rare or endemic herbaceous plants that grow on the slopes of Vihren are edelweiss (Leontopodium alpinum),^[11] Pirin poppy (Papaver degenii),^[12] Oxytropis urumovii,^[13] Alyssum pirinicum,^[14] Timmia norvegica,^[15] Thymus perinicus,^[16] etc.

The fauna includes various bird species, small mammals and abundant populations of chamois.^[6]

Vihren is among the 100 Tourist Sites of Bulgaria under No. 2 and stamps to verify the visit can be found in the Museum of Nikola Vaptsarov in Bansko and in Vihren refuge.^[6] The summit is part of the initiative of the Bulgarian Tourist Union "Conqueror of the Top Ten Mountain Peaks" to promote mountaineering.^[17]

Vihren was first climbed in winter on 9 January 1925 by T.Atanasov, D.Stoykov, V.Baynov and N.Bozhinov.^[4] The classical route to climb the peak is from the Vihren refuge (1,950 m) to the south via the Kabata saddle; this route takes three to four hours in summer and is steep, reaching denivelation of almost 1,000 m in а short time.^[6] Other routes include those from the Banderitsa refuge (1,810 m) or across the knife-edge crest Koncheto from the north. From the Kazanite cirques in the north there is a 400 m-high steep wall which has several tracks from alpine climbing.^[4] This wall was first climbed in 1934 by the German alpinists W.Mosel and F.Auer; in winter it was first ascended in 1949 by Al.Belkovski and Vl.Lobodin.^[18]

From the top there is a view to almost the whole of northern Pirin, as well as to the mountain ranges of Rila, Rhodope, Maleshevo, Ograzhden, Belasica and Slavyanka.^[19]

Vihren Peak on Livingston Island in the South Shetland Islands, Antarctica is named after Vihren.

• Pirin
• Kutelo
• Pirin National Park
• List of mountains in Bulgaria
• Geography of Bulgaria
• List of mountains of the Balkans
• Southernmost glacial mass in Europe
• List of European ultra-prominent peaks
• List of the highest European ultra-prominent peaks
• Most isolated major summits of Europe
• List of mountain ranges

• Мичев (Michev), Николай (Nikolay); Михайлов (Mihaylov), Цветко (Tsvetko); Вапцаров (Vaptsarov), Иван (Ivan); Кираджиев (Kiradzhiev), Светлин (Svetlin) (1980). Географски речник на България [Geographic Dictionary of Bulgaria] (in Bulgarian). София (Sofia): Наука и култура (Nauka i kultura).
• Душков (Dushkov), Добри (Dobri) (1972). Пирин. Туристически речник [Pirin. Tourist Dictionary] (in Bulgarian). София (Sofia): Наука и култура (Nauka i kultura).
• Grunewald, Karsten; Jörg Scheithauer (2010). "Europe's southernmost glaciers: response and adaptation to climate change" (PDF). Journal of Glaciology. 56. International Glaciological Society: 129–142. ISSN 0022-1430. Archived from the original (PDF) on 2 April 2015. Retrieved 6 March 2015.

• "Pirin National Park". Official Site of Pirin National Park. Retrieved 6 December 2017.
• "Official Site of the Bulgarian Tourist Union". Retrieved 16 December 2017.
• "Ultra Prominent Peaks". Retrieved 16 December 2017.
• "Vihren". Peakbagger.com. Retrieved 16 December 2017.
• "Vihren webcam at 1972m". Retrieved 29 July 2020.