Roads and outlines: OpenStreetMap. Ground slopes: elevation data, where available. The 3D ground uses the newest EOX Sentinel-2 cloudless mosaic we can reach (2025, falling back to 2024–2020 or bundled tiles), or a north-up aerial photo you supply, sized from its 1:N scale and aligned to that satellite layer. Building heights use mapped values or estimates. Doors, windows and foundations are generated, not surveyed. Mapped fences and trees are placed when present; a photo stage also guesses terracotta roofs, tree canopies and grassy yards. No Google imagery is collected. GovMap tiles are not downloaded automatically.