The main western fault line, 8 km long (5 miles) and 5 km (3 miles) wide, is divided by many prominent landmarks. Each part is named differently. The most renowned one, Almannagja, is a part of the assembly area of the ancient parliament. To the east of the Parliamentary Plains one of the thousands of chasms of the rift valley was used to burn sorcerers and witches at the stake during the late middle ages, and was named accordingly The Fire Chasms.

The former main road through the Almannagja fault crossed a bridge, which still stands, across the Axe River. The so-called Drowning Pool by the bridge was much deeper before the natural separation under the bridge was lowered with explosives. There women, who were sentenced to death, were put into canvas sacks, weighed down with stones, and thrown in. The capital punishment was introduced late in the 13^th century and abolished in 1929.

Many of the almost innumerable chasms of the Graben, a very young natural phenomenon, are filled with slow flowing, clear fresh water with constant temperature (3-4°C), which prevents it from freezing over. The water volume of those chasms, the Axe River and another stream spilling into the lake, only supply it with about 10% of the volume of its discharge, the Salmon River Sog.