>>30033269
Contour lines!, notable rocks, cliffs, paths. Use different, simple colour distinctions. Thickness of forest / brush maybe as well, depending on how large the area is.

Are you sure there aren't any real maps on the area?

https://www.trails.com/maps.aspx

>>30033269
First, get a simple black and white copy map of whatever area it is you're trying to map. Your local city, county or state should have base maps that show the most common things like roads and property boundaries.
Take map into field and establish a few key landmarks that you can reliably transfer their ground location to the map.
Do this with as many things of interest as you can.
Next, use a good compass and a cruisers hip chain, measuring wheel or rangefinder you can measure direction and distance between your landmarks and the other features and points of interest.
Then, using an engineers scale and your compass, scale these features onto your map with your measured bearing and distances

Download/buy a USGS quadrangle map for the area you're interested in. Take a GPS and mark out any features you're interested in.

Or use GIS with an aerial photo and draw whatever you want.

>>30033367
>>30033502
>>30033543

Thanks for your input. The USGS quadrangle maps look perfect, but I´m in Europe and they only cover the US. Wanted to end up with two maps you can put on top of each other, one for tunnels and one normal with trails etc.

>>30033655
Which country?

>>30033667
Germany.

Some barracks are surprisingly unguarded and vulnerable to theft and arson.

Why not just print out a large version of Google Maps w/terrain features on and mark up what trails/landmarks you need?

>>30036201
Copyrighted, unable to print whole pages.

>>30033655
Does Germany have a geologic survey comparable to USGS that would publish maps like ours?

>>30036482
Screencap does wonders.

>>30033269
There are no gps devices that can track underground. Best you can hope for is a step counter and a compass.