The Balm ruins are the remains of a fortified cave dwelling in the Jura Mountains, in the municipality of Balm bei Günsberg. It is that canton's only cave stronghold and one of the few in Switzerland.
The stronghold was built 20 metres high in a natural cave of about 20 metres wide and 6 metres deep.
The outer wall was provided with two doorways and some narrow windows. The wet rock face was covered with a lining wall; and the rest was a simple two-story timber construction, which is shown evident by the presence of holes into which beams were inserted. While being restored, the presently visible wall openings were distorted from their original form. At a later stage in the building of the stronghold, a fortified, inhabited house with an inside width of 3.5 metres and a length of 29 metres was erected in the forecourt. Presumably this was a defensive fortification of some farming complex.
The entrance to the stone fortress stretched over a long, partly walled rise which is partly hewn from the rock. The connection between the forecourt and the fortress itself is still only incompletely reconstructed. The present-day rise is of modern source, and only partly represents its original state.
Excavations from the years 1939 and 1941 indicate that the place had been used as a habitation since early times.
References:The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.