The longest place-name still in use is Taumatawhakatan- gihangakoauauotamateaturipukakapikimaungahoronukupokai- whenuakitanatahu, it's a New Zealand hill.
I know a longer one... somewhere in whales though >.<
H?
Harry
Hare
Hair
Hop
H... ... Country... ... uh... No idea XD