An iconic fairytale Gothic royal castle dating back nearly 700 years has gone up for sale for an astonishing GBP 17.4 million.

Neu-Ems Castle was built on a hillside overlooking a picture-postcard Austrian valley in 1343 for the region's ruler, Knight Ulric I, with the blessing of the Holy Roman Emperor.

Since 1843, it has been in the hands of the aristocratic Waldburg-Zeil family, who transformed it into a state-of-the-art private hotel nine years ago (2016).

Picture shows the Glopper Castle in Vorarlberg, Austria, undated. It has been listed for sale. Note: Image is a screenshot from video. (Newsflash/NX)

Now the Alpine hotel, with 1,220 square metres of land, two nearby towns and sensational views over the Rhine Valley amid the richest ski resorts in Europe, is up for sale, and is believed to be priced somewhere in the EUR 20 million range (GBP 17.4 million), according to local media reports.

Its imposing stone exterior hides a completely modernised luxury resort venue which, say experts, could be turned back into a breathtaking home for one very wealthy family.

Picture shows the interior of the Glopper Castle in Vorarlberg, Austria, undated. It has been listed for sale. Note: Image is a screenshot from video. (Newsflash/NX)

The original castle was severely damaged in a peasants' revolt in Vorarlberg in 1407, which led to some of the region breaking away to join neighbouring Switzerland.

By 1430, the building, also known as Glopper Castle, had been fully rebuilt and became home to generations of kings and aristocrats.

German estate agents Engel & Voelkers are said to be handling offers on the property.

(Joseph Golder / newsX)