Burg Linz, Medieval castle in Linz am Rhein, Germany.

Burg Linz is a lowland castle of four two- and three-storey wings, partly timber-framed, enclosing a square inner courtyard. It stands inside the old town walls just north of the Rheintor, now separated from the Rhine by the B42. The surviving corner tower from the founding period is round in its lower two-thirds and octagonal above, with a steep Gothic roof. A double staircase leads to the south portal; a second entrance is in the east wing.

Engelbert von der Mark, Elector and Archbishop of Cologne, began building Burg Linz in 1365, a few years after the town received its charter from Heinrich von Virneburg between 1304 and 1332. The archbishop moved the Rhine toll from Andernach to Linz after that town's 1359 revolt. The construction cost 30,000 Cologne marks, borrowed money, so the finished castle was pledged to the Electorate of Trier for eight years. In 1707 the electoral administration moved here from Altenwied, requiring an almost complete rebuild.

The castle's name changed with its uses: in the 18th century it was called "Schloss Linz", and locals later knew it as "Feiths Burg" after the toll collector Anton Feith, who bought it in 1821. Today the private complex hosts weddings, conferences and parties, and for a time a medieval torture chamber and a Roman glass-blowing workshop could be visited there.

The castle stands in the old town just north of the Rheintor, now separated from the Rhine by the B42 road and the railway line. From the Burgplatz, a two-flight staircase leads up to the south portal; a second entrance is in the east wing. The former moat was filled in and is now the Burgplatz itself.

The 1365 build cost Engelbert von der Mark 30,000 Cologne marks, money he had to borrow; after completion he pledged the castle to the Electorate of Trier for eight years. The toll privilege itself had been transferred from Andernach to Linz in 1359 after that city's revolt.