A Multi-Seasonal Solar Landscape System: Cultural and Archaeological Implications of Monumental Shadow Interactions in the Bosnian Valley of the Pyramids

Large-scale solar alignments in archaeological contexts are typically treated as single-event phenomena, most often associated with solstices or equinoxes. The Bosnian Valley of the Pyramids presents a different pattern: a sequence of repeated solar interactions distributed across the annual cycle. This paper analyzes shadow relationships between the Bosnian Pyramids of the Sun, the Moon, and Love using LiDAR-derived elevation models, geodetic data, and solar geometry, supported by multi-season field observations. At the summer solstice, the shadow of the Bosnian Pyramid of the Sun extends toward the Bosnian Pyramid of the Moon. At mid-summer (early August), the same shadow reaches the summit of the Bosnian Pyramid of the Moon. At the equinox, two concurrent interactions are recorded: the shadow of the Sun Pyramid approaches from the northern sector, while the shadow of the Love Pyramid extends along an east-west axis across the same structure. At the winter solstice, the Bosnian Pyramid of the Moon is positioned between opposing shadow trajectories from both sides of the valley. These patterns match calculated solar azimuths and are consistent across both observed and modeled data. Rather than isolated alignments, the evidence reveals a recurring seasonal sequence embedded in the landscape’s spatial organization. This configuration indicates a systematic relationship between monument placement and the annual solar cycle, supporting the interpretation of the valley as an integrated observational landscape.