Nested three-word spatial addressing
Every 12.5 m square in Chennai has three words. Unlike what3words, they tell you where you are.
Word one names a 5 km region, word two a 250 m locality, word three a 12.5 m spot inside it. The words at each level are arranged by meaning, so nearby places sound alike — and any prefix is itself a valid, coarser address.
Marina Beach, Triplicane
Three words, three scales
Each level divides its parent into an exact 20 × 20 block, so containment is exact by construction and reading the address is reading the hierarchy.
- Word 1 · Regioncavern5 km squarewhich 5 km part of the metropolitan area. Drawn from landscape & water.
- Word 2 · Localityorganza250 m squarewhich 250 m block within that region. Drawn from materials, colour & texture.
- Word 3 · Spotpanther12.5 m squarewhich 12.5 m square within that block. Drawn from living things.
Hierarchical, so it is truncatable
Share just the first word to give your position to 5 km and no finer. Progressive disclosure is a privacy control that a flat scheme structurally cannot offer.
Topological, so neighbours exist
Adjacency is a ±1 step in a mixed-radix lattice. You can ask for the cell to the east, walk a row, or test containment by comparing prefixes — no geometry required.
Honest about what it costs
A wrong word lands you nearby rather than on another continent, which makes mistakes quiet. That trade-off is measured, published, and shown on every address.
Questions
- How is this different from what3words?
- what3words is deliberately flat and scrambled: every square is the same size and neighbouring squares have unrelated words, so a mistake lands on another continent and is obviously wrong. Ooru is the inverse — the three words are nested (5 km, then 250 m, then 12.5 m) and drawn from semantically ordered vocabularies, so the address tells you where you are and can be truncated to disclose less.
- What area does it cover?
- A fixed 50 km by 60 km extent anchored in UTM zone 44N over the Chennai Metropolitan Area, from Ennore in the north to Muttukadu in the south and out past Poonamallee in the west.
- How precise is an address?
- Three words name a 12.5 m square — about 156.25 m², roughly a doorway. That is finer than the accuracy of a phone's GNSS fix, which is the limit that actually matters.
- Do I need an account or an API key?
- No. Encoding and decoding are pure arithmetic over a committed word table — there is no database and no lookup service. The map works without any API key at all.