From top secret Headquarters to underground tunnels and under wraps societies, there are some of the places across the globe that one can only visit virtually on Google Maps and not for real. The reason may be because they are too protected, dangerous or too exclusive for some people only.

Maps are created with one layer, but you can have up to 10. On your computer, sign in to My Maps. Open or create a map. You'll see your layers in the box on the left.

Addresses for everyone. What are Plus Codes? Plus Codes are like street addresses for people or places that don't have one. Instead of addresses with street names and numbers, Plus Codes are based on latitude and longitude, and displayed as numbers and letters.

Google Maps, in particular, can track every step you (or at least your smartphone) take and archives that activity as a personal map, dubbed Timeline. The feature helps users (and the internet) remember places you go, routes to destinations, and trips you take.