The first mention of Maribor in an official document dated to 20 October 1164 states the name of Marchburg, which literally means a fortress in the border area.

The fortress was established to protect the German lands from the Hungarians, Drago Oman of the Maribor regional museum told the STA.

The town itself began developing only 90 years later, when Maribor was first described as a square. The settlement on the Drava river banks became a town by 1254.

The original fortress located atop of what is now the Piramida hill burnt down and was long forgotten when a small chapel was built in the 19th century in the same spot.

Today, the Piramida hill is a popular hike for the locals but many are not aware that it used to be the location of the fortress that developed into what is now Slovenia's second largest city.

The foundations of the fortress have been discovered only recently and former Maribor Mayor Franc Kangler even promised in 2012 to set up an open-air museum; however excavation works have ground to a halt since then.

Events to honour the anniversary of the first written mention will be held throughout the year, beginning with Saturday's session followed by a performance of acclaimed actor Jure Ivanušič at Glavni trg square.