Try my mediumregion, I have used it hundreds of times.
[WORLD_GEN]
[TITLE:TOMIS MEDREGION]
[DIM:129:129]
[EMBARK_POINTS:3200] note
[END_YEAR:780]
[BEAST_END_YEAR:600:50]
[REVEAL_ALL_HISTORY:1]
[CULL_HISTORICAL_FIGURES:0]
[ELEVATION:1:400:700:300]
[RAINFALL:0:100:560:560]
[TEMPERATURE:18:68:150:420]
[DRAINAGE:0:100:400:300]
[VOLCANISM:0:100:800:800]
[SAVAGERY:0:100:900:500]
[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]
[MINERAL_SCARCITY:610] note
[MEGABEAST_CAP:38]
[SEMIMEGABEAST_CAP:160]
[TITAN_NUMBER:43]
[TITAN_ATTACK_TRIGGER:30:7000:50000]
[DEMON_NUMBER:4]
[NIGHT_CREATURE_NUMBER:0] note, no bogeymen
[GOOD_SQ_COUNTS:99:800:503]
[EVIL_SQ_COUNTS:200:2000:1800]
[PEAK_NUMBER_MIN:6]
[PARTIAL_OCEAN_EDGE_MIN:0]
[COMPLETE_OCEAN_EDGE_MIN:0]
[VOLCANO_MIN:15] note
[REGION_COUNTS:SWAMP:260:1:1]
[REGION_COUNTS:DESERT:400:3:3]
[REGION_COUNTS:FOREST:1040:3:3]
[REGION_COUNTS:MOUNTAINS:200:2:2]
[REGION_COUNTS:OCEAN:400:1:1]
[REGION_COUNTS:GLACIER:10:1:1]
[REGION_COUNTS:TUNDRA:20:1:1]
[REGION_COUNTS:GRASSLAND:1200:3:3]
[REGION_COUNTS:HILLS:1200:3:3]
[EROSION_CYCLE_COUNT:750]
[RIVER_MINS:400:350] note
[PERIODICALLY_ERODE_EXTREMES:1]
[OROGRAPHIC_PRECIPITATION:1]
[SUBREGION_MAX:3500]
[CAVERN_LAYER_COUNT:3] note this section
[CAVERN_LAYER_OPENNESS_MIN:73]
[CAVERN_LAYER_OPENNESS_MAX:73]
[CAVERN_LAYER_PASSAGE_DENSITY_MIN:4]
[CAVERN_LAYER_PASSAGE_DENSITY_MAX:4]
[CAVERN_LAYER_WATER_MIN:16]
[CAVERN_LAYER_WATER_MAX:70]
[HAVE_BOTTOM_LAYER_1:1]
[HAVE_BOTTOM_LAYER_2:1]
[LEVELS_ABOVE_GROUND:4]
[LEVELS_ABOVE_LAYER_1:7]
[LEVELS_ABOVE_LAYER_2:4]
[LEVELS_ABOVE_LAYER_3:3]
[LEVELS_ABOVE_LAYER_4:3]
[LEVELS_ABOVE_LAYER_5:3]
[LEVELS_AT_BOTTOM:2]
[CAVE_MIN_SIZE:90]
[CAVE_MAX_SIZE:400]
[MOUNTAIN_CAVE_MIN:120]
[NON_MOUNTAIN_CAVE_MIN:160]
[ALL_CAVES_VISIBLE:1]
[SHOW_EMBARK_TUNNEL:2]
[TOTAL_CIV_NUMBER:56]
[TOTAL_CIV_POPULATION:100000]
[SITE_CAP:850] note, for adventurer
[PLAYABLE_CIVILIZATION_REQUIRED:1]
[ELEVATION_RANGES:1380:200:1000]
[RAIN_RANGES:1200:1500:1000]
[DRAINAGE_RANGES:2080:4160:2080]
[SAVAGERY_RANGES:2080:2000:1500]
[VOLCANISM_RANGES:2080:3100:1500]