The village of Ragunovo once stood on an island of the same name in the center of the lake. The Nicholas chapel in this former village was built around the early 19th century. Initially, it consisted of a main log structure and a small vestibule. The prayer room had two identical windows with a three-frame design, located on the northern and southern sides, which have been preserved in their original form. The vestibule had no windows and was lit only through a slightly open door. The main room and vestibule were covered by a common log roof. Originally, the roofing was traditional, as evidenced by the traces of two hens on the upper crowns. The chapel likely ended with a simple cross. Judging by the absence of traces on the western wall, there was no porch.

During the second phase of construction, the chapel's walls were covered with wide boards with a profiled edge, nailed with forged nails. This likely occurred in 1880, as confirmed by an inscription on the preserved door frame. At this time, the roofing was probably replaced with a simple shingle roof, also secured with forged nails. A porch may have been added, as a carved column was found in a later extension, reused. The appearance of the chapel at this stage raises many questions.

In the final phase of construction in the early 20th century, the vestibule was expanded by cutting through the western wall and adding a frame extension. A window was made in the southern wall of the extension. The new entrance was designed with a wide opening featuring a rounded upper lintel and double doors. An open porch appeared in front of the entrance, with thin carved columns and a gable roof. It is likely that a dome also emerged at this stage. The chapel was surrounded by a fence, which has not survived but is visible in an old photograph. Its location can be determined by the boulders that have grown into the ground.

In 2011-2013, the Nicholas chapel was restored. The funding for the work was mainly provided by V.I. Egorov. Organizational issues and material procurement were handled by the National Park and personally by Deputy Director V.M. Gudy. The work was carried out by carpenters from the city of Onega: V.I. Kazakov, S.V. Golovchenko, V.I. Rogachev, as well as local resident V. Bely.