For example, for the UK: Mount Everest is named after Sir George Everest, Vancouver after Captain George Vancouver, and Pittsburgh after William Pitt (the Elder).
Places don't have to be on Earth: eg the Kuyper Belt and Oort Cloud are perfectly valid suggestions for the Netherlands (though so is Tasmania).
PS since no Bulgarians have posted (yet) I'll just leave this here: https://en.wikipedia.org/wiki/Bulgarian_toponyms_in_Antarctica