I'm still playing 40d16 because after effectively days of searching I found
the perfect site, featuring:
-Everything you need to get your fort going (trees, all neighbors, etc.)
-Obsidian as top layers
-Brook
-Magma pipe
-Sand
-Sedimentary layers containing flux (chalk) and LOADS of magnetite ore and bauxite
-Chasm (CS silk)
-Bottomless pit
-Underground pool
-HFS/Adamantine
All on a 5x5 square, if I remember correctly.
If someone is interested, here are the worldgen parameters:
[WORLD_GEN]
[TITLE:LARGE]
[SEED:3654015276]
[HISTORY_SEED:1424962528]
[NAME_SEED:2846205336]
[DIM:257:257]
[END_YEAR:1050]
[BEAST_END_YEAR:250:75]
[REVEAL_ALL_HISTORY:1]
[CULL_HISTORICAL_FIGURES:1]
[ELEVATION:1:400:800:800]
[RAINFALL:0:100:400:400]
[TEMPERATURE:38:42:400:400]
[DRAINAGE:0:100:400:400]
[VOLCANISM:0:100:400:400]
[SAVAGERY:0:100:400:400]
[ELEVATION_FREQUENCY:1:1:1:1:1:1]
[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:100:1000:2000]
[EVIL_SQ_COUNTS:100:1000:2000]
[PEAK_NUMBER_MIN:30]
[OCEAN_EDGE_MIN:0]
[VOLCANO_MIN:40]
[REGION_COUNTS:SWAMP:1032:7:6]
[REGION_COUNTS:DESERT:1032:7:6]
[REGION_COUNTS:FOREST:4128:13:12]
[REGION_COUNTS:MOUNTAINS:8256:9:9]
[REGION_COUNTS:OCEAN:500:1:1]
[REGION_COUNTS:GLACIER:0:0:0]
[REGION_COUNTS:TUNDRA:0:0:0]
[REGION_COUNTS:GRASSLAND:8256:13:12]
[REGION_COUNTS:HILLS:8256:13:12]
[EROSION_CYCLE_COUNT:250]
[RIVER_MINS:400:400]
[PERIODICALLY_ERODE_EXTREMES:1]
[OROGRAPHIC_PRECIPITATION:1]
[SUBREGION_MAX:2750]
[CAVE_MIN_SIZE:5]
[CAVE_MAX_SIZE:25]
[MOUNTAIN_CAVE_MIN:110]
[NON_MOUNTAIN_CAVE_MIN:220]
[ALL_CAVES_VISIBLE:0]
[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:55]
[TOTAL_CIV_POPULATION:20000]
[PLAYABLE_CIVILIZATION_REQUIRED:1]
[ELEVATION_RANGES:8256:16512:3000]
[RAIN_RANGES:8256:16512:8256]
[DRAINAGE_RANGES:8256:16512:4000]
[SAVAGERY_RANGES:8256:16512:8256]
[VOLCANISM_RANGES:8256:16512:8256]
Notable information: murky pools dry out in summer, initially the local fire imps and giant bats can pose a threat and you have to dig a while until you find raw gems. Otherwise the site is immaculate.
You should find it with the site finder, remember this is for 40d16!