how do I post a fb message that I am at a certain location

[AC Question]

I want to post a picture of my location

 

[hallux]

Take the picture, one of the share options should be Facebook (provided you have the app installed).

Alternatively, you could open the Facebook app, start making a post and one of the options is to take a picture to share.

AndroidCentral even has a tutorial.. How to share a picture from your Android phone to Facebook | Android Central

During the posting of the picture is also an ability to add a location, if you so desire.