diff --git a/README.md b/README.md
index 69e5242..e8986b8 100644
--- a/README.md
+++ b/README.md
@@ -40,7 +40,7 @@ int main()
     for (seed = 0; ; seed++)
     {
         // Apply the seed to the generator for the Overworld dismension.
-        applySeed(&g, 0, seed);
+        applySeed(&g, DIM_OVERWORLD, seed);
 
         // To get the biome at a single block position, we can use getBiomeAt().
         int scale = 1; // scale=1: block coordinates, scale=4: biome coordinates
@@ -95,7 +95,7 @@ int main()
     setupGenerator(&g, MC_1_18, LARGE_BIOMES);
 
     uint64_t seed = 123LL;
-    applySeed(&g, 0, seed);
+    applySeed(&g, DIM_OVERWORLD, seed);
 
     Range r;
     // 1:16, a.k.a. horizontal chunk scaling
@@ -172,7 +172,7 @@ int main()
         for (upper16 = 0; upper16 < 0x10000; upper16++)
         {
             uint64_t seed = lower48 | (upper16 << 48);
-            applySeed(&g, 0, seed);
+            applySeed(&g, DIM_OVERWORLD, seed);
             if (isViableStructurePos(structType, &g, p.x, p.z, 0))
             {
                 printf("Seed %" PRId64 " has a Pillager Outpost at (%d, %d).\n",
@@ -248,7 +248,7 @@ int main()
         for (high = 0; high < 0x10000; high++)
         {
             uint64_t seed = s48 | (high << 48);
-            applySeed(&g, 0, seed);
+            applySeed(&g, DIM_OVERWORLD, seed);
 
             if (isViableStructurePos(styp, &g, pos[0].x, pos[0].z, 0) &&
                 isViableStructurePos(styp, &g, pos[1].x, pos[1].z, 0) &&
@@ -290,7 +290,7 @@ int main()
 
     Generator g;
     setupGenerator(&g, mc, 0);
-    applySeed(&g, 0, seed);
+    applySeed(&g, DIM_OVERWORLD, seed);
 
     pos = getSpawn(&g);
     printf("Spawn: (%d, %d)\n", pos.x, pos.z);
diff --git a/finders.c b/finders.c
index c108494..58f61d9 100644
--- a/finders.c
+++ b/finders.c
@@ -2214,21 +2214,20 @@ int isViableStructureTerrain(int structType, Generator *g, int x, int z)
         return 1;
     }
 
-    id = getBiomeAt(g, 4, (x+sx)>>2, 15, (z)>>2);
-    if (isOceanic(id) || id == river || id == frozen_river)
-        return 0;
-    id = getBiomeAt(g, 4, (x)>>2, 15, (z+sz)>>2);
-    if (isOceanic(id) || id == river || id == frozen_river)
-        return 0;
-    id = getBiomeAt(g, 4, (x+sx)>>2, 15, (z+sz)>>2);
-    if (isOceanic(id) || id == river || id == frozen_river)
-        return 0;
-
-    return 1;
+    // approx surface height using depth parameter (0.5 ~ sea level)
+    const double thresh = 0.48;
+    int nptype = g->bn.nptype;
+    g->bn.nptype = NP_DEPTH;
+    int ret =
+        sampleClimatePara(&g->bn, (x+ 0)/4.0, (z+ 0)/4.0) < thresh ||
+        sampleClimatePara(&g->bn, (x+sx)/4.0, (z+sz)/4.0) < thresh ||
+        sampleClimatePara(&g->bn, (x+ 0)/4.0, (z+sz)/4.0) < thresh ||
+        sampleClimatePara(&g->bn, (x+sx)/4.0, (z+ 0)/4.0) < thresh;
+    g->bn.nptype = nptype;
+    return ret;
 }
 
 
-
 /* Given bordering noise columns and a fractional position between those,
  * determine the surface block height (i.e. where the interpolated noise > 0).
  * Note that the noise columns should be of size: ncolxz[ colheight+1 ]
diff --git a/layers.h b/layers.h
index 621b005..9a3f344 100644
--- a/layers.h
+++ b/layers.h
@@ -466,7 +466,7 @@ int sampleBiomeNoise(const BiomeNoise *bn, int64_t *np, int x, int y, int z,
 /**
  * Initialize BiomeNoise for only a single climate parameter.
  * If nptype == NP_DEPTH, the value is sampled at y=0. Note that this value
- * changes linearly with the height (i.e. += y/32).
+ * changes linearly with the height (i.e. -= y/128).
  */
 void setClimateParaSeed(BiomeNoise *bn, uint64_t seed, int large, int nptype);
 double sampleClimatePara(const BiomeNoise *bn, double x, double z);