Interactive Geo Maps is a free WordPress by Carlos Moreira, there is also a premium version, with many additional features.
The plugin generates interactive, responsive, touch-enabled SVG maps which are embeded directly into your HTML5 pages and compatible with all modern browsers and devices.
BASIC FEATURES INCLUDE:
Create as many maps as you want
Responsive and cross-device
Color countries
Add round coloured markers
Set hover color change
Set click actions, like open a new window
Choose from different map projections (Mercator, Miller, NaturalEarth1, among others)
Select which regions to display in a map
Exclude specific regions from a map
Display HTML tooltips on hover
Zoom controls and Pan
PRO ONLY FEATURES INCLUDE:
Colour regions and markers individually
Change initial zoom and center
Cluster markers
Add Legend
Custom images as markers
Vector icons as markers
Text Labels
Display content on click outside the map
Display content in a lightbox
Group regions
Create heatmaps (choropleth maps)
Add lines connecting markers
Overlay different maps (have US states map on world map for example)
Populate map automatically from existing categories or Tags
Advanced zoom options
Plugin homepage: https://interactivegeomaps.com