The Lens
Move the cursor to open a spyglass onto the past. Step through time with the arrow keys; press 1–4 for overlays.
The glass sits at the centre of the map. Drag to move the world beneath it, or tap to set it down somewhere else.
↑↓ basemap · ←→ lens era · 1–4 overlays · space all lens · shift all base · c link · esc clear