Downloading Overture Data

Overture Maps distributes data as GeoParquet files on Amazon S3. No AWS credentials are required.

Full Planet Download

aws s3 sync --no-sign-request \
  s3://overturemaps-us-west-2/release/2025.01.0/ \
  ./data/overture/

Download Specific Themes

To save bandwidth, download only the themes you need:

# Buildings only (~80 GB)
aws s3 sync --no-sign-request \
  s3://overturemaps-us-west-2/release/2025.01.0/theme=buildings/ \
  ./data/overture/theme=buildings/

# Places only (~5 GB)
aws s3 sync --no-sign-request \
  s3://overturemaps-us-west-2/release/2025.01.0/theme=places/ \
  ./data/overture/theme=places/

# Divisions only (~2 GB)
aws s3 sync --no-sign-request \
  s3://overturemaps-us-west-2/release/2025.01.0/theme=divisions/ \
  ./data/overture/theme=divisions/

Directory Structure

geolith expects the standard Overture Maps directory layout:

data/overture/
├── theme=base/
│   ├── type=land/
│   │   ├── part-00000.parquet
│   │   ├── part-00001.parquet
│   │   └── ...
│   ├── type=land_cover/
│   ├── type=land_use/
│   ├── type=water/
│   └── type=infrastructure/
├── theme=buildings/
│   └── type=building/
│       ├── part-00000.parquet
│       └── ...
├── theme=divisions/
│   ├── type=division/
│   ├── type=division_area/
│   └── type=division_boundary/
├── theme=places/
│   └── type=place/
├── theme=transportation/
│   ├── type=connector/
│   └── type=segment/
└── theme=addresses/
    └── type=address/

The theme=X/type=Y/ structure is how Overture partitions its data. geolith scans this tree and maps each theme/type combination to the appropriate layer.

Supported Themes and Types

GERS Bridge Files

The Overture Global Entity Reference System (GERS) provides bridge files that map OSM element IDs to Overture GERS UUIDs. geolith uses these to automatically deduplicate features that appear in both data sources.

Downloading Bridge Files

aws s3 sync --no-sign-request \
  s3://overturemaps-us-west-2/bridgefiles/2026-02-18.0/dataset=OpenStreetMap/ \
  ./data/gers-bridge/

This downloads approximately 32 GB of Parquet files covering three themes:

Directory Layout

data/gers-bridge/
├── buildings/
│   ├── part-00000.zstd.parquet
│   ├── part-00001.zstd.parquet
│   └── ...
├── transportation/
│   ├── part-00000.zstd.parquet
│   └── ...
└── divisions/
    ├── part-00000.zstd.parquet
    └── ...

Auto-Discovery

Place the gers-bridge/ directory as a sibling of your --data directory:

data/
├── overture/          ← --data points here
│   ├── theme=buildings/
│   └── ...
└── gers-bridge/       ← auto-discovered
    ├── buildings/
    ├── transportation/
    └── divisions/

geolith automatically discovers bridge files when they exist at this location. No extra flags needed.

To override the location, use --bridge-dir:

geolith --data ./data/overture --bridge-dir /mnt/ssd/gers-bridge ...

To disable conflation entirely, use --no-conflate:

geolith --data ./data/overture --no-conflate ...

See the GERS Conflation guide for a detailed walkthrough.

Data Freshness

Overture Maps publishes new releases roughly quarterly. Check the Overture Maps releases page for the latest version and update the S3 path accordingly.

When upgrading releases, download to a new directory to avoid mixing data from different versions:

aws s3 sync --no-sign-request \
  s3://overturemaps-us-west-2/release/2025.04.0/ \
  ./data/overture-2025.04.0/

Bridge files are also versioned — download the matching bridge file release for best deduplication results.