What is monolith-terrain?

Monolith is an interactive 3D map you view in a web browser, styled to look like an old USGS topographic survey sheet combined with a sci fi heads up display. You can either load real elevation data for any place on Earth, or generate a procedural mountain range from scratch, and then explore it in three dimensions with contour lines, colored elevation tinting, a survey grid overlay, spot elevation markers, and clickable peak markers. Navigation is done by dragging to orbit around the terrain, scrolling to zoom, and right dragging to pan. Clicking a marked peak or basin flies the camera in and opens a small data panel about that spot, and clicking the close button returns you to where you were. There is also a cinematic tour mode where you pick a starting and ending point and the camera flies a smooth path between them, plus a radar scan effect that sweeps a wave across the terrain and visibly lifts the surface as it passes. When using real world data you choose a location by picking a preset or entering latitude and longitude, and you can adjust how much area is shown and how exaggerated the vertical relief looks. In procedural mode you get a seeded, tweakable mountain landscape with a hovering monolith and an excavated instrument basin, and every generation parameter can be adjusted live. The whole interface is broken into adjustable panels covering things like the map overlay coloring, surface material, camera depth of field, overall visual look, the heads up display styling, camera and tour motion, and performance settings such as render scale and shadow quality. Under the hood it is built with the Three.js graphics library for rendering, with the map styling injected into the standard shader. It uses the postprocessing library for depth of field, tone mapping, grain, and antialiasing, lil-gui for the parameter panel, and Vite as the build tool, all in plain JavaScript with no framework. Real world elevation comes from the publicly hosted Terrain Tiles dataset, which draws from sources including NASA's SRTM and USGS elevation data, and requires no API key. To run it locally you install dependencies and start the dev server with npm, and it can be built as a static site and deployed to GitHub Pages or Cloudflare. The project is released under the MIT license.