Burgruine Plainburg, Castle ruin in Großgmain, Austria

Burgruine Plainburg is a ruined hilltop castle above the Gmainer Tal at up to 643 m, about 1.5 km by road from Großgmain's centre. What survives are outer walls over five metres high and on average about 1.45 m thick, the inner courtyard and the entrance area with its gatehouse. The gate between the inner and outer courtyards received its present Gothic form in 1674.

Around 1100, Comes Werigandus de Playen built the inner courtyard and gatehouse, and by 1140 the castle was documented as Plagien Castrum, serving the Plain counts until their line ended in 1260. In 1292 it passed to the Archbishops of Salzburg, who used it to protect the salt trade routes; between 1470 and 1800 military alterations were made, and Archbishop Paris von Lodron restored it in 1620. The last soldier left in 1796, after which the fortress decayed.

The site reflects layers of medieval building practices visible in its remaining walls and structures. Visitors can observe how construction techniques and materials changed over the centuries through what survives today.

The climb to the ruins follows marked hiking paths through the local landscape around Großgmain. Plan your visit for dry weather to navigate safely on the uneven paths and steps that lead to the site.

Construction workers discovered skeletal remains embedded within the walls during renovation in the 1970s. This find hints at events and stories hidden within the fortress beyond its documented military use.