"Pretty decent" here stands for
MAGMA and
AWESOMEI ran this with Dig Deeper and got the following region:
It has:
A sinister scorching savanna next to an evil ocean with an aquifer, sand and Magma. For those who like it rough.
A 4x4 embark with an UG river, HFS, sand, Magma and up to 6 chasm tiles. When you need a little one with a big hole.
A big seaside cliff next to a haunted ocean. With sand and Magma. If you want to build a huge erection.
A mini ocean that fits a single embark. With sand and Magma. For the watersport fans.
An evil area with either a chasm, UG river, Magma and a cave site. In case the anthromorphs are your thing.
OR a seaside HFS spot if you want some good old domination on the beach.
A 7x5 mountain range in a haunted tundra with UG Pool, UG River, some trees, Chasm, Pit, HFS, Sand and Magma. Use protection.
There are also multiple locations with variations of the above, so even if you have the weirdest of preferences, you can feel right at home cause this baby has it all! (Look out for the cave sites in the world map, since those tiles are all mountains. Some of them are pretty small areas so there are lots of features huddled together)
All the races are alive, and if you want to see some fun interracial action, I suggest building a bridge to the little continent in the southeast corner. There are some elves there that have never been in contact with the outside world before. (There is a tile that can be bridged)
Every single tile in the region has a magma pool and a magma pipe.Most of these should appear regardless of your mod.
Without further ado, I present you the
[WORLD_GEN]
[TITLE:VOLCANIC]
[SEED:316397692]
[HISTORY_SEED:460785245]
[NAME_SEED:2820163364]
[DIM:65:65]
[END_YEAR:1000]
[BEAST_END_YEAR:100:30]
[REVEAL_ALL_HISTORY:1]
[CULL_HISTORICAL_FIGURES:0]
[ELEVATION:1:400:1600:1600]
[RAINFALL:0:100:180:180]
[TEMPERATURE:-10:110:250:250]
[DRAINAGE:0:100:200:200]
[VOLCANISM:100:100:200:200]
[SAVAGERY:0:100:400:400]
[ELEVATION_FREQUENCY:2:1:1:1:1:1]
[RAIN_FREQUENCY:1:1:1:1:1:1]
[DRAINAGE_FREQUENCY:1:1:1:1:1:1]
[TEMPERATURE_FREQUENCY:1:1:1:1:1:1]
[SAVAGERY_FREQUENCY:1:1:1:1:1:1]
[VOLCANISM_FREQUENCY:1:1:1:1:1:1]
[GOOD_SQ_COUNTS:0:0:0]
[EVIL_SQ_COUNTS:300:400:500]
[PEAK_NUMBER_MIN:0]
[OCEAN_EDGE_MIN:1]
[VOLCANO_MIN:180]
[REGION_COUNTS:SWAMP:300:4:0]
[REGION_COUNTS:DESERT:69:3:0]
[REGION_COUNTS:FOREST:200:3:0]
[REGION_COUNTS:MOUNTAINS:0:0:0]
[REGION_COUNTS:OCEAN:0:0:0]
[REGION_COUNTS:GLACIER:0:0:0]
[REGION_COUNTS:TUNDRA:0:0:0]
[REGION_COUNTS:GRASSLAND:100:1:0]
[REGION_COUNTS:HILLS:0:0:0]
[EROSION_CYCLE_COUNT:200]
[RIVER_MINS:50:50]
[PERIODICALLY_ERODE_EXTREMES:1]
[OROGRAPHIC_PRECIPITATION:1]
[SUBREGION_MAX:5000]
[CAVE_MIN_SIZE:50]
[CAVE_MAX_SIZE:100]
[MOUNTAIN_CAVE_MIN:150]
[NON_MOUNTAIN_CAVE_MIN:0]
[ALL_CAVES_VISIBLE:1]
[SHOW_EMBARK_RIVER:2]
[SHOW_EMBARK_POOL:2]
[SHOW_EMBARK_M_POOL:2]
[SHOW_EMBARK_M_PIPE:2]
[SHOW_EMBARK_CHASM:2]
[SHOW_EMBARK_PIT:2]
[SHOW_EMBARK_OTHER:2]
[SHOW_EMBARK_TUNNEL:2]
[TOTAL_CIV_NUMBER:20]
[TOTAL_CIV_POPULATION:20000]
[PLAYABLE_CIVILIZATION_REQUIRED:1]
[ELEVATION_RANGES:60:5:0]
[RAIN_RANGES:0:0:0]
[DRAINAGE_RANGES:0:0:0]
[SAVAGERY_RANGES:0:0:0]
[VOLCANISM_RANGES:0:0:80]
The gen will probably report an error before finishing and generating the world may give you over a thousand rejects.