Popular place names as baby names in the U.S. currently include Savannah (#38), Austin (#73), London (a high of #85 in 2013, now #131), Lydia (#80), and Brooklyn (#34).
Other formerly trendy place names, which now aren’t so popular, include China, Asia, India, Virginia (high of #6 in 1921; fell out of the Top 100 in 1960; now down to #515), Odessa (high of #278 in 1908–09; last charted in 1956), Adelaide (high of #181 in 1884; fell out of the Top 1000 in 1949; re-entered in 2005; up to #258 in 2016), Georgia (high of #81 in 1882; #226 in 2016). and Florence (Top 10 from 1886–1906, with a high of #6 five of those years).
Some interesting place names which are a bit more under the radar, which I feel work very well as people names, include:
Vienna, or Vienne
Sahara (means “desert” in Arabic)
Isauria, or Isaura
Petra (Also a feminine form of Peter, in addition to a city in Jordan. The name is #2 in Croatia, #26 in Hungary, #31 in Bosnia, #73 in the Czech Republic, and #93 in Portugal.)
Rona, or Rhona (means “rough island” in Scottish)
Siena, or Sienna (#236 in the U.S., #32 in New Zealand, #20 in Australia, #28 in England and Wales, #68 in Scotland and Canada, #53 in Northern Ireland, and #71 in Ireland)
Skye (one of those names I can only picture working on just the right person, in this case someone with very fair features and an ethereal, super-sweet disposition)
Gilead (means “monument of testimony” in Hebrew)
Lennox (possibly means “place of elms” in Scottish)
Merritt (means “boundary gate” in Old English)