It's not a war movie yet, but is an amazing story so that Steven Spielberg and Tom Hanks starting to work on it. it's possible that Brad Pitt is interested too. The Castle Itter is still standing, in fact is now of privately owned and used as a residence.

The Battle for Castle Itter in the Austrian North Tyrol village of Itter was fought on May 5, 1945, in the last days of the European Theater of World War II. It may have been the only battle in the war in which Americans and Germans fought side-by-side. Popular accounts of the battle have called it the "strangest" battle of World War II.

Maj Sepp Gangl of the Wehrmacht switched sides to help US forces (Via)

Troops of the 23rd Tank Battalion of the 12th Armored Division of the US XXI Corps led by Captain John C. "Jack" Lee, Jr., a number of Wehrmacht soldiers, a Waffen SS officer who defected, and recently freed French POWs defended Castle Itter against an attacking force from the 17th SS Panzergrenadier Division until relief from the American 142nd Infantry Regiment of the 36th Division of XXI Corps arrived.

Itter Castle is a small castle on a hill in Austria that was built during the medieval period in the 13th century. By the time of World War II, it was used by the Nazis to incarcerate prominent French prisoners. The castle was first seized by an SS officer in February 1943 and was being used as part of a prison facility by April of that same year. Notable prisoners over the next two years included former French prime ministers and generals, as well as a French tennis star and Charles de Gaulle's older sister. 

The commander of the prison fled on May 4, 1945 and many of the SS guards departed the castle soon afterwards. A German major, Josef Gangl, was commanding German anti-Nazi soldiers in the closing days of the war. American Lieutenant John C. Lee, seen here at the right, volunteered to lead the rescue of the French prisoners at Itter Castle accompanied by Major Gangl and his German soldiers. 

US Capt Jack Lee teamed up with Gangl's men to take on the SS (Via)

The rescue party included 14 Americans, 10 anti-Nazi Germans, and two Sherman tanks. While en route, the small party defeated a group of SS troops that had been attempting to block a road. One of the tanks was left behind to guard a bridge on the route. 

When the Americans and Germans arrived and freed the French prisoners at Itter Castle, Lee and Gangl placed their men in defensive positions throughout the castle, while the single tank was placed at the main entrance.

On the morning of May 5, 1945, a small force of Nazi SS soldiers began their attack on the castle. The Sherman tank provided machine gun fire for the soldiers inside the castle until it was destroyed by the SS troops. 

An M4A3E8 Sherman tank, the same model as Besotten Jenny, displayed at the former Patton Museum of Cavalry and Armor (Via)

During the ensuing battle, French prisoners fought alongside the American and German soldiers against the Nazi SS. When a relief force of the American 142nd Infantry Regiment arrived the SS were defeated. The German Major Gangl died during the battle from an SS sniper and has been honored as an Austrian national hero. The American Lieutenant Lee received the Distinguished Service Cross and was promoted to Captain for his actions. 

Schloss Itter was damaged in the fighting as this May 1945 photo shows (Via)

The Battle for Castle Itter remains a small, lesser known event of the end of the war. It's notable for being the only battle in which American and German soldiers fought together as allies and the only battle in which American troops defended a medieval castle.

If you'd like to learn more about the Battle of Castle Itter, check out Stephen Harding's book titled The Last Battle: When U.S. and German Soldiers Joined Forces in the Waning Hours of the World War II in Europe.