Assuming you're asking about the features of an actual map,
- Title (Possibly a building, could be a city name, state or country)
- orientation (where is north) Cartographers today, put North (N) at the top of the map but that hasn't always been the same.
- Scale, though while not key to find that said building, but is a crucial part of the map making crafting. if the map is not to scale, that should be prominent.
- Longitude and Latiude, also not required for that building as mentioned, but desireable for surveyors and even more helpful with today's modern GPS systems.
- an index grid for ease of navigation
- a legend (or symbols translator), showing highway markers, buildings, uses stylized symbols and shapes sometimes.
other necessary information of maps may also include but not limited to: (direction, title, legend, scale, author/creator, date of creation, labels, border, sources of information, etc.)
hope this helps!