Type these in the in-game chat (press Enter to open chat).
!pindrop an unnamed dot where you stand!pin <text>drop a dot with a label!pin <type> <text>a typed pin, e.g. !pin house Base!undoPinremove your most recent pin!deletePin <text>remove the pin matching that text!deletePinwith no text, removes your most recent unnamed pinOr on this map, signed in: tap walked ground and Pin here, or tap a pin to relabel, retype, move or delete it.
Each row of the sidebar's Legend is a switch, remembered by this browser; the Layers card on the map holds presets of them, details (torches and fires, deaths, trails), and swaps the ground between the terrain render and a flat atlas of biomes (L cycles). Zoomed right in, builds turn from roofs into a floor plan; hide floor plan when close to keep the roofs. Portal lines join linked pairs, and a grave is gear still lying there.
Drag the little figure from the buttons onto walked ground (on a phone: tap it, then tap the map), or pick 3D under View in the Layers card, or See in 3D on a place or a pin, and you stand there at eye height. Drag to look around, scroll or pinch to zoom the eye, W A S D or the arrows to walk (Shift runs), click the ground to walk there; ⇅ circles the spot from above, where the same keys fly you over the land (E or Space rise, Q or Shift sink). Map or Esc brings you back to the map where you stood. Buildings, trees and rocks are the game's own models, mined rocks as far as they have been mined.
Press M in game and turn on visible to other players. Without it you still show in the online list, but never with a location.
Players and pins refresh every few seconds; builds and the explored mask every minute while someone has the map open.