Avoid using 'locus' as a direct substitute for 'location' in everyday speak; it's more specific. The train station is a busy location, not a locus of activity.
Pro Tip 2/3
Abstract Focus
'Locus' often refers to an abstract point or center where something important occurs. The university served as the locus for the protest.
Pro Tip 3/3
Formal Speech
Prefer 'locus' in formal or academic contexts to add precision to your language. This city is the locus of important trade agreements.