HOENN
The island as one with the sea
A semi-tropical island nation sitting near Johto, Hoenn is considered to be a bit unique (at least until everyone heard about Alola). While not the largest, Hoenn is the pioneer region of scientific advancement and is a bit of a buddy-buddy region with everyone else.
GEOGRAPHY
Hoenn is a volcanic island, and harbors a variety of landscapes - but for the most part, it's all very green. Areas near the southeastern side of Mt. Chimney are quite dry due to a rampage caused by Groudon thousands of years ago, in stark contrast to the rest of the region. The region has a rather expansive underground cavern, which has yet to be properly documented. The underground regions are from a time when Groudon send a whole bunch of the island underground. It serves as a time capsule, so scientists don't like to mess with it much. The island also has smaller islands surrounding it, the most notable of which is where Sootopolis city is located: inside a giant meteorite crater. It's believed the meteor hit before humans inhabited the island.
HISTORY
Hoenn has a bit of a messy history, stemming from the fact that it's home to a very active trio of legends. The gods of sea, land, and sky live in Hoenn, and it's due to this that the region has undergone significant geological and divine conflicts over the years. But despite everything thrown at them from the powers above, the people of Hoenn persevered and built the region as it is today.
Originally, Hoenn was governed by 3 individual factions, but the 3 came together to create the region in harmony with one another (mostly).
POPULATION
The population of Hoenn is generally one of the most varied and diverse, only rivaled in this factor by Unova. The population is generally more densely concentrated in the larger cities, with the smaller towns slowly falling behind while populations age. Hoenn has the second smallest population of all the regions, above Alola.
As far as the pokemon population goes, it's rather diverse as well, though a major chunk of Hoenn's pokedex is aquatic (which is fair due to the region being an island). The region is home to many native Hoenn pokemon, as well as pokemon who've found their way to the island over time.