Heritage building structures in many situations contribute unique value to national cultural heritage. In engineering practice, monitoring of historic structures includes visual assessment. This article assesses the condition of the concrete in one of the most recognizable buildings in Łódź, the former German Reformed Gymnasium, located at Tadeusza Kościuszki Avenue. The paper reports a visual assessment of the structure and the degree of technical wear affecting selected structural components of the building. A historical analysis of the building’s state of preservation, characterization of the structural system, and an assessment of the condition of the floor-slab concrete were carried out. The state of preservation of the eastern and southern facades of the building was found to be satisfactory, while on the western side (with the courtyard) the facade is in a poor state of preservation. Tests were also conducted out on concrete samples taken from individual ceilings. The concrete cores were tested for compressive strength, water absorption, density, porosity, and carbonation depth. Corrosion processes including the degree of carbonization and the phase composition of the concrete were identified by X-ray diffraction. The results are indicative of the high quality of the concrete produced more than 100 years ago.

The purpose of the article is to show how a city can develop in symbiosis with its natural environment and protected area, which is in line with the idea of sustainable development. The study examines the role and importance of post-mining land reclamation in restoring the natural values of degraded areas. The authors present the theme of the symbiosis between architecture and unique nature—understood simultaneously as natural and cultural heritage—using the example of the Polish city of Kielce and its surroundings. This is an area rich in green spaces, including protected ones, within and around which urban space is developing and where both historical and contemporary architecture is situated. This study demonstrates that symbiosis, the protection of nature, and cultural heritage are key elements of contemporary design. The city and architecture can thrive in post-mining areas, and the reclamation process, as the research suggests, can catalyse the creation of architecture that is deeply embedded in the landscape, complementing it rather than competing with it. Social surveys conducted for this study indicate that residents of the region recognise and appreciate the need to protect natural resources and integrate architecture with nature, demonstrating the relevance and timeliness of the issues addressed.