Origin of the name Ljubljana
The origin of the name Ljubljana is not entirely clear. Historians have not been in accord, though presumably it roots even to the pre-Roman times. The Romans named the city Iulia Emona, which was burned down by Huns in the 5th century. It is likely that it could have evolved from the Roman word alluviana, which stands for flooding river also. In the 6th the territory was settled by first Slavic tribes, forefathers of modern Slovenians, but only at the start of the 12th century names Laibach and Luwigana emerged. Laibach is of German origin and presumably derived from Laubach, marshland. Luwigana, a Slavic-Roman word, is more similar to the modern name, when w could haved turned into b and g to l. Some believe the name could have derived from the name of the old Slavic diety Laburus, while a general belief, that it originates from Slovenian word ljubljena (beloved), is uncertain as well. Since we love it, the last explanation should suffice.
How to pronounce Ljubljana?
For non Slavic nations the word Ljubljana is not easy to pronounce. Italians and Spanish have shortened it to Lubiana, while Austrians and Germans rarely name it Laibach nowdays.
The -lj- connection inside the word is pronounced similarly to English word million or saying call you with no pause. Although Slovenians when speaking colloquial, often do not pronounce Js inside the word – lublana. Just use the one you find it easier J. Locals will not resent you.