Ljubljana, the capital and most populous city in Slovenia, is also its largest. It is Slovenia’s administrative, cultural, educational, and political center.

In the same area stood a Roman city named Emona during antiquity. Ljubljana was mentioned for the first time in the second half of the 12th Century. It is located at the center of a trade route between the Danube and the northern Adriatic Seas. It was once the capital of Carniola, a Slovene-inhabited area of the Habsburg Monarchy. Habsburg ruled it from the Middle Ages to the fall of the Austro–Hungarian Empire in 1918. Ljubljana was made the capital of the Socialist Republic of Slovenia after World War II. It is now part of the Socialist Federal Republic of Yugoslavia. This status remained until 1991, when Slovenia gained independence. Ljubljana was made the capital of the new state.

Koper is Slovenia’s fifth-largest city. Koper, located in the Istrian region in the southwestern portion of Slovenia, is the country’s largest coastal city. It is approximately five kilometers (3 miles) south of the border with Italy and twenty kilometers (12 mi) from Trieste. It is bordered by the satellite cities of Ankaran and Izola. It is a valuable natural resource because of its unique ecology and biodiversity. The only container port in Slovenia, the Port of Koper, is a key contributor to the economic activity of the Municipality of Koper. Ankaran decided to leave the municipality through a 2011 referendum to create its municipality due to the Port of Koper’s influence on tourism. It is the destination of many Mediterranean cruising lines. Koper, home to approximately 25,000 people, is the central urban area of Slovenian Istria. Ales Brzan, the current mayor, has been serving since 2018.

Officially, Koper is bilingual in Slovene as well as Italian. Koper is home to the 15th-century Praetorian Palace, Loggia in Venetian Gothic, the 12th-century Carmine Rotunda Church, and the 14th-century tower at St. Nazarious’ Cathedral.

Maribor is the second largest city in Slovenia and also the largest city in the traditional region of Lower Styria. It is also home to the City Municipality of Maribor and the Eastern Slovenia region. Maribor is eastern Slovenia’s administrative, cultural, and economic center.

Maribor was mentioned first as a castle in 1164. It was also described as a settlement and city in 1209 and 1254. Like most Slovene ethnic areas, Maribor was under Habsburg control until 1918, when Rudolf Maister’s men secured the city to the State of Slovenes, Croats, and Serbs. The Kingdom of Serbia formed the Kingdom of Yugoslavia. Maribor was annexed to independent Slovenia in 1991.

Ptuj, a town in northeastern Slovenia, is the seat of the Municipality of Ptuj. Ptuj is the oldest known city in Slovenia. It was established as a Roman military fort. Ptuj was strategically located at the Drava River crossing, part of a prehistoric trade route linking the Adriatic and the Baltic Sea.

This area was once part of the Austria-Hungarian Empire and is now part of the traditional Styria region. Most residents in the area were ethnic Germans during the 20th century, but most of today’s inhabitants are Slovene. Ptuj residents are called Ptujcani (Slovene for “Ptujcani”).

Celje is Slovenia’s fourth-largest municipality. It is the regional center of the traditional Slovenian area of Styria and the administrative seat of Celje City Municipality (Slovene: Mestna Obcina Celje). Celje is situated below Upper Celje Castle (407 m or 1,335 ft) at the confluence of the Savinja and Hudinja rivers in the lower Savinja Valley. It also crosses Ljubljana and Maribor roads to Velenje and the Central Sava Valley. It is located at 238 m (781 feet) above the mean sea level (MSL).