Earth Sandwich / City antipodes / Philadelphia
Antipode finder · United States
The antipode of
Philadelphia.
Draw a straight line from Philadelphia (39.95° N, 75.16° W) through the centre of the Earth and it comes out at 39.95° S, 104.84° E, in the Indian Ocean, 1,100 km from the nearest dry land, off the coast of Australia. The other slice of an Earth sandwich would sink.
- Philadelphia
- 39.95° N, 75.16° W · about 40 m above sea level · 1,573,916 people
- Antipode
- 39.95° S, 104.84° E
- What is there
- The Indian Ocean; the sea floor there lies about 4,520 m below the surface
- Nearest dry land
- 1,100 km from the antipode, on the coast of Australia
- Nearest town
- Augusta, Australia · 1,108 km from the antipode
- Nearest big city
- Perth · 1,331 km from the antipode
- Sandwich verdict
- SOGGY the other slice lands in open water
- Nearest exact spot
- 2,360 km away, 34 km from Lamar, United States ⇄ 1,410 km from Port-aux-Français, French Southern Territories
Can you make an Earth sandwich from Philadelphia?
No, not from Philadelphia itself. The other slice would land in the Indian Ocean, 1,100 km from the nearest dry land (Australia), where the sea floor lies about 4,520 m below the surface. Boats do not count (Sandwich Law § 1.3).
The nearest place from which an exact Earth sandwich is possible is 2,360 km from Philadelphia, 34 km from Lamar, United States. Its other slice would go down 1,410 km from Port-aux-Français, French Southern Territories.
Philadelphia is on the The US & Canada ↔ the southern Indian Ocean corridor. Its guide lists where every city on both sides lands and how to make an Earth sandwich there.
How this was worked out: the antipode flips the latitude and moves the longitude by 180°. Land or sea comes from the OpenStreetMap coastline the map uses; the sandwich verdict and elevations come from the verifier's 0.2° grid (Natural Earth land, ETOPO 2022 relief); water names from Natural Earth; towns and populations from GeoNames. The city's position is GeoNames' point for it; a big city's suburbs spread tens of kilometres around that point, and the figures move with them. Generated 2026-09-29.