Grid Point Code

Play

Hang Sơn Đoòng

near Xuân SơnQuảng BìnhVietnam

With a code
#K606F-C5H4P
Said aloud
Hang Sơn Đoòng C5H4P

Open in the playground

What the code says

The Grid Point Code for Hang Sơn Đoòng is #K606F-C5H4P. It names a cell 2.56 m north to south and 3.26 m east to west, centred on 17°27'24.97"N, 106°17'14.99"E, and it turns back into that cell on any phone or computer by arithmetic alone: no network, no account, no lookup table.

What it is
Largest cave passage in the world, located near the Laos-Vietnam border
Code
#K606F-C5H4P
With a check character
#K606F-C5H4P*J
Short form
C5H4P
Cell centre
17.456936, 106.287498
Cell size
2.56 m by 3.26 m
Region
Quảng Bình
Country
Vietnam

How to give this address

On a sign, a form or a delivery note

The whole code, #K606F-C5H4P. It needs nothing else: no city, no street, no network to read it back.

Said aloud, in Quảng Bình

Hang Sơn Đoòng C5H4P: a name both people know, then the last five characters. They give back the exact code for anywhere within 4.0 km north or south and 5.1 km east or west of Hang Sơn Đoòng. Further away the same five name somewhere else, which is why the whole code is what goes on a sign.

Copied by hand, or read over a phone

#K606F-C5H4P*J. The character on the end catches any single mistyped symbol and any two neighbours swapped.

As a link or a square code

Open it on the map, move to the exact door, and add directions if the code needs help: "blue gate, second floor". The link and the square code carry them. Nothing is kept on this site.

From the city to the door

The first four characters name a cell about 40 km by 51 km here. Each one after that picks one of 25 inside the last, so the whole ten name a spot about the size of a doorway.

  1. K606Metropolitan area40 km by 51 km
  2. K606FDistrict8 km by 10.2 km
  3. K606FCSuburb1.6 km by 2.04 km
  4. K606FC5A few streets320 m by 408 m
  5. K606FC5HBuilding64 m by 81.6 m
  6. K606FC5H4Entrance12.8 m by 16.3 m
  7. K606FC5H4PDoorway2.56 m by 3.26 m

More in Vietnam

Place and region from Wikidata, described on Wikipedia; nearby town from GeoNames, under CC BY 4.0.