diff --git a/LICENSE.txt b/LICENSE.txt
index 11ce895..f0b5f69 100644
--- a/LICENSE.txt
+++ b/LICENSE.txt
@@ -5,7 +5,7 @@ Sounds and textures are under various licenses, see the license.txt file in the
 License for Code
 ----------------
 
-Copyright (C) 2018 FaceDeer
+Copyright (C) 2021 FaceDeer
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
diff --git a/pit_caves/LICENSE.txt b/pit_caves/LICENSE.txt
new file mode 100644
index 0000000..1b07b15
--- /dev/null
+++ b/pit_caves/LICENSE.txt
@@ -0,0 +1,22 @@
+License for Code
+----------------
+
+Copyright (C) 2021 FaceDeer
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
\ No newline at end of file
diff --git a/pit_caves/init.lua b/pit_caves/init.lua
new file mode 100644
index 0000000..36ebeef
--- /dev/null
+++ b/pit_caves/init.lua
@@ -0,0 +1,196 @@
+local modpath = minetest.get_modpath(minetest.get_current_modname())
+local S = minetest.get_translator(minetest.get_current_modname())
+
+local min_depth = tonumber(minetest.settings:get("pit_caves_min_bottom") or -2500)
+local max_depth = tonumber(minetest.settings:get("pit_caves_max_bottom") or -500)
+local min_top = tonumber(minetest.settings:get("pit_caves_min_top") or -100)
+local max_top = tonumber(minetest.settings:get("pit_caves_max_top") or 100)
+
+assert(min_depth < max_depth, "pit_caves_min_bottom is above pit_caves_max_bottom")
+assert(min_top < max_top, "pit_caves_min_top is above pit_caves_max_top")
+assert(max_depth < min_top, "pit_caves_max_bottom is above pit_caves_min_top")
+
+local pit_radius = 3 -- approximate minimum radius of pit - noise adds a lot to this
+
+local region_mapblocks = tonumber(minetest.settings:get("pit_caves_mapblock_spacing") or 16)
+local mapgen_chunksize = tonumber(minetest.get_mapgen_setting("chunksize"))
+local pit_region_size = region_mapblocks * mapgen_chunksize * 16
+
+local c_air = minetest.get_content_id("air")
+local c_gravel = c_air
+if minetest.get_modpath("default") then
+	c_gravel = minetest.get_content_id("default:gravel")
+end
+
+local water_level = tonumber(minetest.get_mapgen_setting("water_level"))
+local mapgen_seed = tonumber(minetest.get_mapgen_setting("seed")) % 2^16
+
+local scatter_2d = function(min_xz, gridscale, border_width)
+	local bordered_scale = gridscale - 2 * border_width
+	local point = {}
+	point.x = math.floor(math.random() * bordered_scale + min_xz.x + border_width)
+	point.y = 0
+	point.z = math.floor(math.random() * bordered_scale + min_xz.z + border_width)
+	return point
+end
+
+-- For some reason, map chunks generate with -32, -32, -32 as the "origin" minp. To make the large-scale grid align with map chunks it needs to be offset like this.
+local get_corner = function(pos)
+	return {x = math.floor((pos.x+32) / pit_region_size) * pit_region_size - 32, z = math.floor((pos.z+32) / pit_region_size) * pit_region_size - 32}
+end
+
+local get_pit = function(pos)
+	local corner_xz = get_corner(pos)
+	local next_seed = math.random(1, 1000000000)
+	math.randomseed(corner_xz.x + corner_xz.z * 2 ^ 8 + mapgen_seed + 1)
+
+	local location = scatter_2d(corner_xz, pit_region_size, 0)
+	local depth = math.floor(math.random() * (max_depth - min_depth) + min_depth)
+	local top = math.floor(math.random() * (max_top - min_top) + min_top)
+	
+	math.randomseed(next_seed)
+	return {location = location, depth = depth, top = top}
+end
+
+local perlin_params = {
+	offset = 0,
+	scale = 1,
+	spread = {x=30, y=30, z=30},
+	seed = 45011,
+	octaves = 3,
+	persist = 0.67
+}
+local data = {}
+
+minetest.register_on_generated(function(minp, maxp, seed)
+	if minp.y > max_top or maxp.y < min_depth then
+		return
+	end
+
+	local pit = get_pit(minp)
+	
+	if pit == nil then
+		return -- no pit in this map region
+	end
+	
+	local location_x = pit.location.x
+	local location_z = pit.location.z
+	
+	-- early out if the pit is too far away to matter
+	-- The plus 20 is because the noise being added will generally be in the 0-20 range, see the "distance" calculation below
+	if	location_x - 20 > maxp.x or 
+		location_x + 20 < minp.x or 
+		location_z - 20 > maxp.z or
+		location_z + 20 < minp.z
+	then
+		return
+	end
+	
+	local top = pit.top
+	local depth = pit.depth
+
+	local vm, emin, emax = minetest.get_mapgen_object("voxelmanip")
+	local area = VoxelArea:new{MinEdge=emin, MaxEdge=emax}
+	vm:get_data(data)
+
+	local nvals_perlin = mapgen_helper.perlin3d("pit_caves:pit", emin, emax, perlin_params)
+		
+	for vi, x, y, z in area:iterp_xyz(emin, emax) do
+	
+		local distance_perturbation = (nvals_perlin[vi]+1)*10
+		local distance = vector.distance({x=x, y=y, z=z}, {x=location_x, y=y, z=location_z}) - distance_perturbation
+		local taper_min = top - 40
+
+		if y < top and y > depth then
+		
+			-- taper the top end
+			if y > top - 40 then
+				distance = distance - ((taper_min - y)/2)
+			end
+			
+			if distance < pit_radius then
+				if y < depth + 20 and data[vi] ~= c_air then
+					data[vi] = c_gravel
+				else
+					data[vi] = c_air
+				end
+			end
+		end
+	end
+	
+	--send data back to voxelmanip
+	vm:set_data(data)
+	--calc lighting
+	vm:set_lighting({day = 0, night = 0})
+	vm:calc_lighting()
+	vm:update_liquids()
+	--write it to world
+	vm:write_to_map()
+end)
+
+----------------------------------------------------------------------------------------------
+-- Debugging and sightseeing commands
+
+function round(val, decimal)
+  if (decimal) then
+    return math.floor( (val * 10^decimal) + 0.5) / (10^decimal)
+  else
+    return math.floor(val+0.5)
+  end
+end
+
+local send_pit_state = function(pos, name)
+	local pit = get_pit(pos)
+	if pit == nil then
+		return false
+	end
+	local location = {x=math.floor(pit.location.x), y=pit.top, z=math.floor(pit.location.z)}
+	minetest.chat_send_player(name, S("Pit at @1, bottom @2", minetest.pos_to_string(location), pit.depth))
+	return true
+end
+
+local send_nearby_states = function(pos, name)
+	local retval = false
+	retval = send_pit_state({x=pos.x-pit_region_size, y=0, z=pos.z+pit_region_size}, name) or retval
+	retval = send_pit_state({x=pos.x, y=0, z=pos.z+pit_region_size}, name) or retval
+	retval = send_pit_state({x=pos.x+pit_region_size, y=0, z=pos.z+pit_region_size}, name) or retval
+	retval = send_pit_state({x=pos.x-pit_region_size, y=0, z=pos.z}, name) or retval
+	retval = send_pit_state(pos, name) or retval
+	retval = send_pit_state({x=pos.x+pit_region_size, y=0, z=pos.z}, name) or retval
+	retval = send_pit_state({x=pos.x-pit_region_size, y=0, z=pos.z-pit_region_size}, name) or retval
+	retval = send_pit_state({x=pos.x, y=0, z=pos.z-pit_region_size}, name) or retval
+	retval = send_pit_state({x=pos.x+pit_region_size, y=0, z=pos.z-pit_region_size}, name) or retval
+	return retval
+end
+
+minetest.register_chatcommand("findpit", {
+    params = "pos", -- Short parameter description
+    description = S("find the pits near the player's map region, or in the map region containing pos if provided"),
+    func = function(name, param)
+		if minetest.check_player_privs(name, {server = true}) then
+			local pos = {}
+			pos.x, pos.y, pos.z = string.match(param, "^([%d.-]+)[, ] *([%d.-]+)[, ] *([%d.-]+)$")
+			pos.x = tonumber(pos.x)
+			pos.y = tonumber(pos.y)
+			pos.z = tonumber(pos.z)
+			if pos.x and pos.y and pos.z then
+				if not send_nearby_states(pos, name) then
+					minetest.chat_send_player(name, S("No pits near @1", minetest.pos_to_string(pos)))
+				end
+				return true
+			else
+				local playerobj = minetest.get_player_by_name(name)
+				pos = playerobj:get_pos()
+				if not send_nearby_states(pos, name) then
+					pos.x = math.floor(pos.x)
+					pos.y = math.floor(pos.y)
+					pos.z = math.floor(pos.z)
+					minetest.chat_send_player(name, S("No pits near @1", minetest.pos_to_string(pos)))
+				end
+				return true
+			end
+		else
+			return false, S("You need the server privilege to use this command.")
+		end
+	end,
+})
diff --git a/pit_caves/locale/template.txt b/pit_caves/locale/template.txt
new file mode 100644
index 0000000..654affe
--- /dev/null
+++ b/pit_caves/locale/template.txt
@@ -0,0 +1,11 @@
+# textdomain: pit_caves
+
+
+### init.lua ###
+
+No pits near @1=
+Pit at @1, bottom @2=
+You need the server privilege to use this command.=
+
+find the pits near the player's map region, or in the map region containing pos if provided=
+
diff --git a/pit_caves/mod.conf b/pit_caves/mod.conf
new file mode 100644
index 0000000..5785838
--- /dev/null
+++ b/pit_caves/mod.conf
@@ -0,0 +1,4 @@
+name = pit_caves
+description = Inserts very tall "pit" caves underground
+depends =
+optional_depends = mapgen_helper, default
\ No newline at end of file
diff --git a/pit_caves/settingtypes.txt b/pit_caves/settingtypes.txt
new file mode 100644
index 0000000..7805edc
--- /dev/null
+++ b/pit_caves/settingtypes.txt
@@ -0,0 +1,5 @@
+pit_caves_min_bottom (Lower limit of bottoms of pits) int -2500
+pit_caves_max_bottom (Upper limit of bottoms of pits) int -500
+pit_caves_min_top (Lower limit of tops of pits) int -100
+pit_caves_max_top (Upper limit of tops of pits) int 100
+pit_caves_mapblock_spacing (Average number of map blocks between pits) int 16