Musala (9,596 ft) is the highest peak in Bulgaria and the entire Balkan Peninsula. Olympus (2,918 m) is the highest peak in Greece and the second highest in the Balkans. Triglav and Korab are the highest peaks in Slovenia and Macedonia, but neither of them is the third or fourth highest peak in the Balkans. ¹⁾

The Gregorian calendar was introduced in 1582 by Pope Gregory XIII. It corrected the shift of the actual date of the beginning of spring from the Julian calendar and introduced the principle that years with numbers divisible by 100, but not divisible by 400, are not leap years. Therefore, the difference between the calendars is the number of leap years over 400 years. ²⁾

The largest city in Bulgaria is Sofia (1,204,685 inhabitants). The second-largest cities in Bulgaria are Plovdiv (338,153), Varna (334,870), Burgas (200,271), Ruse (149,642). ³⁾

Cyrillic was created in 9th century Bulgaria. Tradition attributes its creation to two saints who converted the Slavs to Christianity - Cyril and Methodius (hence the name of the alphabet). ⁴⁾

The Battle of Varbitza Pass is an armed clash that took place on July 26, 811. The battle is counted as one of the greatest defeats in Byzantine history. The battle was fought by the victorious Bulgarian army led by Khan Krum and the Byzantine army with Emperor Nikephoros. ⁵⁾

The national instrument of Bulgaria is bagpipes called gadulka. ⁶⁾

Bulgarians invented the first electronic computer, the digital watch, and the airbag in the car. ⁷⁾

Bulgaria is one of the largest wine producers in the world, producing 200,000 tons annually. ⁸⁾

A popular drink is Mastika, a spirit made from 47% tree resin. ⁹⁾

Animal bones carved with human markings have been discovered in Korarnika Cave and are some of the earliest examples of symbolic human behavior. ¹⁰⁾

A Bulgarian folk song was featured on the Voyager Gold Record, which was sent into space by NASA. ¹¹⁾

Bulgaria is an ancient country, with people living there for over 6,000 years in some places. ¹²⁾

Bulgaria has its own Bulgarian language. It is a type of Slavic language.¹³⁾

Bulgaria became independent from the Ottoman Empire in 1908. ¹⁴⁾

One of Bulgaria's heroes is Vasil Levski, who led the fight for independence in the late 19th century. ¹⁵⁾

Bulgaria is famous for the production of rose oil, used for perfume. More than 50% of the world's supply comes from here. ¹⁶⁾

Bulgaria is considered the home of yogurt. ¹⁷⁾