I was reading about the 'level increase with distance' option in the update features, and got me thinking about a good way of improving the leveling, just a few random ideas.
I think a great way would be using a block that when placed makes the surrounding area i.e. in exclusively that biome within a 100 x 100 area, spawn pokémon with an average level a certain average amount above the previous level (of the last block that was layed down wherever it may be) i.e. block 1 by defeating your first gym gives levels 10 block 2 from second gym spawns 20's etc.
The block is obtainable through various quests in game such as: completing a gym, catching/evolving a specific pokemon, beating a gym with a specific pokemon to encourage style diversity etc.
the block can be placed once like glass
block themes could be shrines, totems, minerals?
could make offerings, i.e. a stack of coal to temporarily increase the chances of a certain type of pokemon appearing, or pokemon with slightly more likely nature and iv's.
a special award could also be safari block version lasts for 30 mins and spawns pokemon from different biomes or levels after which it disintegrates
higher level places get slightly different spawns, to their low level equivalents, i.e. skarmory only on higher level grass planes
can only obtain one block for each level, so no easy unlimited level 50 blocks for example, to get other blocks a prestige system could be used such as starting from prestige block 1, 2, 3... with different pokemon, over time different biomes can be made high level for eventual access to all pokemon, by prestiging many times.