Complex sentence: By the First World War a total of 9400 marks was raised through other charities and from interest payments, which was used to pay for, amongst other things, the construction of the climbing path, which was also called the "Höllentalgrat".
Split into simpler sentences: By the First World War a total of 9400 marks had been raised through other charities and from interest payments. Among other things, this was used to pay for the construction of the climbing path, which was also called the "Höllentalgrat".