- Griqualand West, Northern Cape Province, South Africa1
- Gumuch-dagh, Ephesus, Izmir, Turkey2
- Haddam, Middlesex County, Connecticut, United States3
- Harpers Ferry, Jefferson County, West Virginia, United States1
- Haute-Vienne, Limousin, France1
- Hellesta, Sweden1
- Hermon, St. Lawrence County, New York, United States1
- Hoboken, Hudson County, New Jersey, United States6
- Hot Springs, Garland County, Arkansas, United States2
- Howes Cave, Cobleskill, Schoharie County, New York, United States1
- Hudson River, New York, United States1
- Hula Valley and Dead Sea, Israel1
- Huntington (Norwich), Hampshire County, Massachusetts, United States1
- Idar-Oberstein, Hunsr'ck, Rhineland-Palatinate, Germany1
- Ikaría (Nicaria), Sámos, Greece1
- Ilfeld, Thuringia, Germany1
- India1
- Indian Creek, Newberry County, South Carolina, United States1
- Iquique, Tarapaca, Chile1
- Iredell County, North Carolina, United States1