STONEHENGE: Geodetic and Solstitial Geometry of the Megalithic Circles and the Sacred Landscape Canon

This paper presents a comprehensive mathematical, geodetic, and astronomical reconstruction of the Stonehenge megalithic complex and its broader landscape matrix. Through an integrated analysis of its concentric stone and earth rings—spanning from the inner Sarsen Horseshoe, through the Sarsen and Z–Y circles, to the outer Aubrey circle—it is demonstrated that the entire ground plan is governed by strict modular coordination derived from the ideal Roman foot (1 i.r.f. = 0.296296... m) and a macro-modular quantum termed the Standard Entity (1 S.E. = 22.5 i.r.f. = 6.666... m), coupled by the harmonic scaling factor k = (10/9)² = 1.23456789... At the local site level, a solstitial gnomonic mechanism is identified wherein a central monolith of height h = 6.0 m (20.25 i.r.f.) at summer solstice noon (solar altitude angle α ≈ 62.36°) projects a shadow length of exactly π meters (10.602875... i.r.f.), yielding an exact rational cubic volume ratio of 3.375. The Station Stones rectangle is demonstrated to form a 5 : 12 : 13 Pythagorean grid defining exactly 60 modular spatial units (S.E.²), which directly corresponds to the 60 primary structural components of the Sarsen Circle (30 uprights and 30 lintels), while its vertices segment the 56-hole Aubrey circle into balanced harmonic intervals (7 + 21 + 7 + 21). The metrological hypothesis is statistically validated through Kendall's cosine quantal analysis across measured architectural radii (q = 0.2963 m, Φ = 4.82, p < 0.001) and stochastic Monte Carlo spatial models yielding p-values between 10⁻¹⁰ and 10⁻²² (>9 σ significance). Across the broader landscape, this geodetic framework is corroborated by the Durrington Walls alignment vector measuring exactly 1,000π meters at an azimuth of 60°, demonstrating the deliberate execution of an advanced, unified geodetic and astronomical canon across Salisbury Plain.