- 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
- Huntington, Suffolk County, New York, United States1
- Idar-Oberstein, Hunsr'ck, Rhineland-Palatinate, Germany1
- Ikaría (Nicaria), Sámos, Greece1
- Ilfeld, Thuringia, Germany1
- Indian Creek, Newberry County, South Carolina, United States1
- Indian Ocean, Pacific Ocean, China Seas1
- Iquique, Tarapaca, Chile1
- Iredell County, North Carolina, United States1
- Ireland1
- Isle Royale, Lake Superior, Keweenaw County, Michigan, United States1
- Isère, Rhône-Alpes, France1
- Italy1
- Jackson County, Georgia, United States1
- Jackson, Hinds County, Mississippi, United States1
- Jackson, Madison County, Tennessee, United States1
- Jacksonville, Duval County, Florida, United States1