Maps - fixed pin point?

Hi.

I've got some supplier data visualised by location, as below, with bubble size inflated by volume quantity.

I'm trying to have the base map effectively have a number of fixed, no volume, locations (i.e. warehouses) that would display as well.

For example, as per the two black stars in the below.

Is it possible to either insert shapes/icons onto the base map that more as the map is moved OR put a secondary data set on?

Or is the only real solution just putting the warehouse locations into the supplier data set with a nominal 'volume' so they show up as larger bubbles? Which would not be ideal because they aren't clearly distinguished from the supplier data then.

Thanks.