Download Administrative Boundary Data from 'geoBoundaries' // Provides tools to download individual country boundaries and global composite boundaries from 'geoBoundaries' https://www.geoboundaries.org/ across multiple administrative ('ADM') levels. Returns boundaries as 'sf' objects for mapping and spatial analysis. Runfola et al. (2020) doi:10.1371/journal.pone.0231866 describe the underlying database.