This is a map I was playing on about 4 years ago.
I think "MegaCanyon" was the seed i used for it.

My first Feed the Beast Mod Map! I used MCedit to build some stuff. I was surprised that MCedit worked with the mod blocks.
NOTE: This map was made with the DIREWOLF20 1.6.4 VERSION modpack. Trying to play it with any other mod pack could cause incongruities and/or corruption of the map.

Hint: thriftworks was the seed i used

I made a layered map with a variety of tree sizes! I used Worldpainter and MCedit to craft this landscape. The trees below the canopy are from a tree schematic pack by lentebriesje. I used a schematic of an epic forest someone made a while back for the main stand of huge trees. I used a cleaned up schematic of a mega tree from another map i found a while back for the MEGA trees, which i made by layering multiple trees together.
I also hid a little book in the map where i tried out writing a small dramatic story thing. Enjoy
Tree links:
original main stand: https://web.archive.org/web/2020/http://www.minecraftworldmap.com/worlds/LYgIM
tree pack (compatible with WorldPainter): http://www.planetminecraft.com/project/native-trees-of-europe-template-repository-1779952/
Unfortunately i don't remember where i found the original mega tree. :/

I made a huge mesa biome map with Worldpainter! Enjoy
I might add some more layers of other biomes and stuff later.

Just a quick test world i made with Worldpainter and some tree schematics file i got somewhere.

Recently I downloaded an old map with an epic forest of mega trees. But, the map was so old it crashed a few times and chunks went missing. So I used MCedit to salvage the remaining piece of intact forest. Then I placed multiple plots of that mega forest schematic onto an AMPLIFIED map. Enjoy!

Credit to the original map i created a huge forest schematic from: https://web.archive.org/web/2020/http://www.minecraftworldmap.com/worlds/LYgIM

Those of you who have seen previous versions of this map might be like, "Oh Niieeewwww! What happened to all the other stuff?". No worries, all the other stuff is safe on another map. I just trimmed down this map to put focus on Some new stuff I made out of boredom.
The Nerdy Notes:
-Created a large swath of lowlands
-built huge dam walls with epic towers
-built huge stairs tower thing
-added random landforms and structures
-built a small floaty structure near spawn
"Version 2.0" of this map soon to come, i think :/

A while ago i downloaded a map where a glitch made a tons of villages spawn on top of each other with no villagers inside. I used MCedit to copy-paste and make the glitch village bigger since huge pieces of it got deleted when the anvil update kicked in a while ago. Also, i trimmed off old chunks with MCedit so the map would run better. Enjoy!