This is very interesting topic. as in our daily life many times we require google maps without internet which earlier was not possible but in the end of 2015 google launched the offline feature. To get this feature you have to follow the below mentioned steps
In your smartphone open google maps app & search the location where you want to go.(For this you should have the internet)
After getting the area click the three line hamburger icon on left side of map search box.Here you will get ‘offline areas’ option
Now you get the + icon on lower side of your screen, after clicking the same you will get the option ‘download this area?’
Drag that map in square box which you want to save. Zoom out this to save more area
Click on ‘download’ once you get the full area in square which you want to download
Here you have to save your area by any name.
Once you download the map then you can get it without internet in ‘Offline areas’ option in settings of google maps.
*Please note that you can only download upto 1.5GB of map*