diff --git a/benchmarks/conformance/shared/fixtures/geography.test.ts b/benchmarks/conformance/shared/fixtures/geography.test.ts
index 6e27fff1..868d382f 100644
--- a/benchmarks/conformance/shared/fixtures/geography.test.ts
+++ b/benchmarks/conformance/shared/fixtures/geography.test.ts
@@ -1,6 +1,7 @@
 import { beagle } from '@tanstack/charts-data/beagle'
 import { learningPoverty } from '@tanstack/charts-data/learning-poverty'
 import { usCountyUnemployment } from '@tanstack/charts-data/us-county-unemployment'
+import { geoContains } from 'd3-geo'
 import { describe, expect, it } from 'vitest'
 import { beagleRoute } from '../../cases/105-route-map/transform'
 import {
@@ -18,15 +19,28 @@ import {
 } from '../transforms/learning-poverty'
 
 describe('geography demo data', () => {
-  it('converts the published world atlases without replacing their geometry', () => {
-    expect(worldCountries).toHaveLength(177)
+  it('converts the published world atlases without New Zealand', () => {
+    expect(worldCountries).toHaveLength(176)
     expect(worldCountries.every(({ id }) => typeof id === 'string')).toBe(true)
+    expect(
+      worldCountries.some(
+        ({ properties }) => properties.name === 'New Zealand',
+      ),
+    ).toBe(false)
     expect(worldLand.geometry.coordinates).not.toHaveLength(0)
     expect(detailedWorldLand.geometry.coordinates).not.toHaveLength(0)
+    expect(geoContains(worldLand, [174.78, -41.29])).toBe(false)
+    expect(geoContains(detailedWorldLand, [174.78, -41.29])).toBe(false)
+    expect(geoContains(worldLand, [151.21, -33.87])).toBe(true)
   })
 
   it('joins learning-poverty rows without changing published values', () => {
-    expect(learningPovertyCountries).toHaveLength(95)
+    expect(learningPovertyCountries).toHaveLength(94)
+    expect(
+      learningPovertyCountries.some(
+        ({ properties }) => properties.name === 'New Zealand',
+      ),
+    ).toBe(false)
 
     const sourceByName = new Map(
       learningPoverty.map((row) => [row['Country Name'], row]),
diff --git a/packages/charts-demo-data/src/country-atlas.ts b/packages/charts-demo-data/src/country-atlas.ts
index e11ea9af..b91dd395 100644
--- a/packages/charts-demo-data/src/country-atlas.ts
+++ b/packages/charts-demo-data/src/country-atlas.ts
@@ -1,7 +1,13 @@
 import countriesAtlasJson from 'world-atlas/countries-110m.json'
+import detailedCountriesAtlasJson from 'world-atlas/countries-50m.json'
 import landAtlasJson from 'world-atlas/land-110m.json'
 import detailedLandAtlasJson from 'world-atlas/land-50m.json'
-import { geoGraticule, geoGraticule10 } from 'd3-geo'
+import {
+  geoCentroid,
+  geoContains,
+  geoGraticule,
+  geoGraticule10,
+} from 'd3-geo'
 import { feature } from 'topojson-client'
 import { simplifyPolygonGeometry } from './simplify-geo'
 import type {
@@ -13,6 +19,8 @@ import type {
 
 type AtlasTopology = Parameters<typeof feature>[0]
 
+const excludedCountryName = 'New Zealand'
+
 export type CountryGeometry = Extract<
   GeoGeometryObjects,
   { type: 'Polygon' | 'MultiPolygon' }
@@ -53,6 +61,8 @@ export const worldCountries: readonly CountryFeature[] =
       return []
     }
 
+    if (entry.properties.name === excludedCountryName) return []
+
     return [
       {
         type: 'Feature',
@@ -65,9 +75,9 @@ export const worldCountries: readonly CountryFeature[] =
     ]
   })
 
-if (worldCountries.length !== 177) {
+if (worldCountries.length !== 176) {
   throw new TypeError(
-    `Expected 177 world-atlas countries, got ${worldCountries.length}`,
+    `Expected 176 world-atlas countries after excluding ${excludedCountryName}, got ${worldCountries.length}`,
   )
 }
 
@@ -77,14 +87,19 @@ export const worldCountryCollection: ExtendedFeatureCollection<CountryFeature> =
     features: [...worldCountries],
   }
 
-export const worldLand = convertLand(landAtlasJson, 'world-atlas land-110m')
+export const worldLand = convertLandWithoutExcludedCountry(
+  landAtlasJson,
+  countriesAtlasJson,
+  'world-atlas 110m',
+)
 export const previewWorldLand: LandFeature = {
   ...worldLand,
   geometry: simplifyPolygonGeometry(worldLand.geometry, 2),
 }
-export const detailedWorldLand = convertLand(
+export const detailedWorldLand = convertLandWithoutExcludedCountry(
   detailedLandAtlasJson,
-  'world-atlas land-50m',
+  detailedCountriesAtlasJson,
+  'world-atlas 50m',
 )
 
 function atlasTopology(value: unknown, label: string): AtlasTopology {
@@ -94,23 +109,62 @@ function atlasTopology(value: unknown, label: string): AtlasTopology {
   return value
 }
 
-function convertLand(value: unknown, label: string): LandFeature {
-  const topology = atlasTopology(value, label)
-  const landObject = topology.objects.land
+function convertLandWithoutExcludedCountry(
+  landValue: unknown,
+  countriesValue: unknown,
+  label: string,
+): LandFeature {
+  const countriesTopology = atlasTopology(countriesValue, `${label} countries`)
+  const countriesObject = countriesTopology.objects.countries
+  if (!countriesObject) {
+    throw new TypeError(`${label} is missing countries`)
+  }
+
+  const convertedCountries = feature(countriesTopology, countriesObject)
+  if (convertedCountries.type !== 'FeatureCollection') {
+    throw new TypeError(`${label} countries did not produce a collection`)
+  }
+  const excludedCountry = convertedCountries.features.find(
+    (country) =>
+      isRecord(country.properties) &&
+      country.properties.name === excludedCountryName,
+  )
+  if (!excludedCountry || !isCountryGeometry(excludedCountry.geometry)) {
+    throw new TypeError(`${label} did not contain ${excludedCountryName}`)
+  }
+
+  const landTopology = atlasTopology(landValue, `${label} land`)
+  const landObject = landTopology.objects.land
   if (!landObject) {
     throw new TypeError(`${label} is missing land`)
   }
-
-  const converted = feature(topology, landObject)
+  const convertedLand = feature(landTopology, landObject)
   const land =
-    converted.type === 'FeatureCollection' ? converted.features[0] : converted
-  if (!land || land.type !== 'Feature' || !isCountryGeometry(land.geometry)) {
-    throw new TypeError(`${label} did not produce polygon geometry`)
+    convertedLand.type === 'FeatureCollection'
+      ? convertedLand.features[0]
+      : convertedLand
+  if (!land || !isCountryGeometry(land.geometry)) {
+    throw new TypeError(`${label} did not produce polygon land geometry`)
+  }
+
+  const polygons =
+    land.geometry.type === 'MultiPolygon'
+      ? land.geometry.coordinates
+      : [land.geometry.coordinates]
+  const includedPolygons = polygons.filter((coordinates) => {
+    const polygon: CountryGeometry = { type: 'Polygon', coordinates }
+    return !geoContains(excludedCountry, geoCentroid(polygon))
+  })
+  if (includedPolygons.length === polygons.length) {
+    throw new TypeError(`${label} land did not contain ${excludedCountryName}`)
   }
 
   return {
     type: 'Feature',
-    geometry: land.geometry,
+    geometry: {
+      type: 'MultiPolygon',
+      coordinates: includedPolygons,
+    },
     properties: {},
   }
 }
diff --git a/packages/charts-demo-data/src/learning-poverty-geography.ts b/packages/charts-demo-data/src/learning-poverty-geography.ts
index 54261752..8035baf0 100644
--- a/packages/charts-demo-data/src/learning-poverty-geography.ts
+++ b/packages/charts-demo-data/src/learning-poverty-geography.ts
@@ -57,9 +57,9 @@ export const previewLearningPovertyCountries: readonly LearningPovertyCountry[]
     geometry: simplifyPolygonGeometry(country.geometry, 2),
   }))
 
-if (learningPovertyCountries.length !== 95) {
+if (learningPovertyCountries.length !== 94) {
   throw new TypeError(
-    `Expected 95 learning-poverty countries in world-atlas, got ${learningPovertyCountries.length}`,
+    `Expected 94 learning-poverty countries in the filtered world-atlas, got ${learningPovertyCountries.length}`,
   )
 }