Torbau mit Resten einer Burg in Simmelsdorf, Medieval castle ruins in Simmelsdorf, Germany

Torbau mit Resten einer Burg in Simmelsdorf is a gate building combined with surviving castle walls situated on elevated terrain in the Nürnberger Land district of Bavaria. The site displays the physical remains of a medieval fortification with the gate structure as its most recognizable feature alongside adjacent wall segments.

The builders and date of the castle's origin are unknown; the Winterstein family likely belonged to the ministeriales of Hiltpoltstein-Rothenberg. The first documented lord, Neidung von Winterstein, sold goods to the Teutonic Order in 1326. By 1378 the whole lordship was held by Albrecht von Egloffstein. In 1450 Nuremberg troops failed to take the castle but burned its outer farms. The Tucher family bought it in 1664 for 18,735 guilders.

The name Winterstein comes from the family that held the castle from the 14th century; Neidung von Winterstein sold goods to the Teutonic Order in 1326. In 1662/64 the Nuremberg patrician family Tucher von Simmelsdorf bought the estate for 18,735 guilders and added "und Winterstein" to its name. A Tucher bailiff then managed the site, which served only occasionally as a hunting residence.

The ruin stands on a hill at 522 m above sea level in the Winterstein district, reached on foot from Simmelsdorf. The two-storey gatehouse with its round-arched passage and the adjoining wall stumps of the main building are the surviving parts; the terrain is uneven and has no visitor facilities.

A 1677 etching after Johann Keill shows the castle far more complete than today: the two-storey gatehouse with a half-timbered oriel, an adjoining building to the east and a round tower. The gatehouse's present upper storey was rebuilt around 1689/90.