The majority of Himmel's surface is covered by idyllic woodlands, groves of fruit trees and large fertile plains interspersed with a vast ocean of salt water teaming with life. There are a large number of lakes fed by rivers flowing from the high mountain ranges that break up the planet in the continent seized-land masses.
Himmel was first visited by the Tau'ri in 1939, when a Nazi expedition went through the Stargate. These first German explorers named the planet "Himmel", the German word for "Heaven", due to it's breathtaking beauty which made in an idyllic paradise with abundant natural resources. They discovered the planet was controlled by creatures with dark serpents in their hearts. Himmel was controlled by the System Lord Nirrti, who used the world as one of her Jaffa breeding worlds. The Nazis the sent an army and more equipment through the gate and fought against Nirrti's forces. The Battle of Heaven was long and bloody but eventually the Nazis took control over Nirrti's remaining troops. After a year, the Nazis had won and began to build a colony on the planet.
Heaven has a population of thousands of "perfect" men and women, and the colony saw no reason to send new resources back to Earth. The colony of Himmel remained forgotten and undiscovered, cut off from the Fatherland and ignorant of the end of World War II. (RPG: "Fantastic Frontiers: Stargate Season One", "First Steps: The Stargate Unexplored Worlds Roleplaying Sourcebook")
The RPG states that Paul Langford is German and brought the Stargate to Germany after it was discovered. Hitler saw the gate as an occult treasure and organized an attempt to unlock its power. They managed to activate it and traveled to Himmel to colonized it. Langford saw what it did and thought they were all crazy. He defected to America and convinced them to capture the gate, which they did. However, later in the series, and in "Stargate: Continuum", this is retconned, stating that the gate was brought to America in 1939 before the Nazis could get their hands on it.