G-43 A landslide is the downward displacement of masses consisting of rocks, debris, or soil by the effect of gravity. The last landslide that occurred in Devrek in 2015 occurred on the northern slope of the V-shaped valley of the Çomaklar Stream, which is a tributary of Devrek Stream, with an average slope of 23%. The slope where the landslide occurred belongs to the Çaycuma formation, which consists of Lower-Middle Eocene aged siltstone, sandstone and mostly claystone. The cutting and filling works on the Devrek-Ereğli Highway, which is under construction, and the risky road in terms of landslides have changed the balance angle of the slope and caused damage to the surrounding buildings. Due to the landslide, 86 buildings were damaged and some of them were completely destroyed. As a precaution, applications such as slope leveling, bored piles, concrete barriers, masonry and drainage channels were applied to the upper mass so that another neighborhood above the landslide rupture zone would not be damaged.