diff --git a/assets/world/structure/natural/ribcage-small.vox b/assets/world/structure/natural/ribcage-small.vox
new file mode 100644
index 0000000000..5b888ae0db
Binary files /dev/null and b/assets/world/structure/natural/ribcage-small.vox differ
diff --git a/assets/world/structure/natural/skull-large.vox b/assets/world/structure/natural/skull-large.vox
new file mode 100644
index 0000000000..3011d3083e
Binary files /dev/null and b/assets/world/structure/natural/skull-large.vox differ
diff --git a/world/src/block/mod.rs b/world/src/block/mod.rs
index 0fb4ab3396..b76624c0da 100644
--- a/world/src/block/mod.rs
+++ b/world/src/block/mod.rs
@@ -366,7 +366,7 @@ pub struct ZCache<'a> {
 impl<'a> ZCache<'a> {
     pub fn get_z_limits(&self) -> (f32, f32) {
         let cave_depth = if self.sample.cave_xy.abs() > 0.9 {
-            (self.sample.alt - self.sample.cave_alt) + 8.0
+            (self.sample.alt - self.sample.cave_alt + 8.0).max(0.0)
         } else {
             0.0
         };
diff --git a/world/src/block/natural.rs b/world/src/block/natural.rs
index 563f21eca0..9003c21f89 100644
--- a/world/src/block/natural.rs
+++ b/world/src/block/natural.rs
@@ -3,6 +3,7 @@ use crate::{
     all::ForestKind,
     column::{ColumnGen, ColumnSample},
     util::{HashCache, RandomPerm, Sampler},
+    CONFIG,
 };
 use common::{assets, terrain::Structure};
 use lazy_static::lazy_static;
@@ -43,11 +44,15 @@ pub fn structure_gen<'a>(
     let st_pos3d = Vec3::new(st_pos.x, st_pos.y, wheight as i32);
 
     let volumes: &'static [_] = if QUIRKY_RAND.get(st_seed) % 64 == 17 {
-        &QUIRKY
+        if st_sample.temp > CONFIG.tropical_temp {
+            &QUIRKY_DRY
+        } else {
+            &QUIRKY
+        }
     } else {
         match st_sample.forest_kind {
             ForestKind::Palm => &PALMS,
-            ForestKind::Savannah => &PALMS,
+            ForestKind::Savannah => &ACACIAS,
             ForestKind::Oak if QUIRKY_RAND.get(st_seed) % 16 == 7 => &OAK_STUMPS,
             ForestKind::Oak => &OAKS,
             ForestKind::Pine => &PINES,
@@ -356,6 +361,16 @@ lazy_static! {
         st_asset("world/tree/snow_pine/7.vox", (16, 15, 12)),
         st_asset("world/tree/snow_pine/8.vox", (12, 10, 12)),
     ];
+
+    pub static ref ACACIAS: Vec<Arc<Structure>> = vec![
+        // snow pines
+        st_asset("world/tree/acacia/1.vox", (16, 17, 1)),
+        st_asset("world/tree/acacia/2.vox", (5, 6, 1)),
+        st_asset("world/tree/acacia/3.vox", (5, 6, 1)),
+        st_asset("world/tree/acacia/4.vox", (15, 16, 1)),
+        st_asset("world/tree/acacia/5.vox", (19, 18, 1)),
+    ];
+
         /*
         // snow birches -> need roots!
         assets::load_map("world/tree/snow_birch/1.vox", |s: Structure| s
@@ -408,4 +423,9 @@ lazy_static! {
         st_asset("world/structure/natural/tower-ruin.vox", (11, 14, 5)),
         st_asset("world/structure/natural/witch-hut.vox", (10, 13, 3)),
     ];
+
+    pub static ref QUIRKY_DRY: Vec<Arc<Structure>> = vec![
+        st_asset("world/structure/natural/ribcage-small.vox", (7, 13, 4)),
+        st_asset("world/structure/natural/skull-large.vox", (15, 20, 4)),
+    ];
 }
diff --git a/world/src/lib.rs b/world/src/lib.rs
index 2f0d76323c..b3dd6071c7 100644
--- a/world/src/lib.rs
+++ b/world/src/lib.rs
@@ -92,7 +92,7 @@ impl World {
 
                 let (min_z, max_z) = z_cache.get_z_limits();
 
-                for z in base_z..(min_z as i32).max(base_z) {
+                for z in base_z..min_z as i32 {
                     let _ = chunk.set(Vec3::new(x, y, z), stone);
                 }
 
diff --git a/world/src/sim/mod.rs b/world/src/sim/mod.rs
index 5cb20482f9..e45be1a799 100644
--- a/world/src/sim/mod.rs
+++ b/world/src/sim/mod.rs
@@ -439,7 +439,7 @@ impl SimChunk {
             forest_kind: if temp > 0.0 {
                 if temp > CONFIG.desert_temp {
                     ForestKind::Palm
-                } else if temp > CONFIG.desert_temp {
+                } else if temp > CONFIG.tropical_temp {
                     ForestKind::Savannah
                 } else {
                     ForestKind::Oak