What was the sister ship of the airship LZ 129 Hindenburg called?

Explanation

LZ 129 Hindenburg was a large German airship, built in 1935. Together with its sister-ship Graf Zeppelin, it was the largest airship ever to be built. It is most known for the Hindenburg-disaster on 6 May 1937 in New Jersey, USA. During the accident, the hydrogen-filled framework of the airship exploded. The accident was a key factor to transport with airships being given up. The ship was named after Paul von Hindenburg, the 2nd German president.