How it's built
The Plaice to Know is a four-stage pipeline that turns the full transcript archive into a ranked, curated map.
1. Extract
The raw input is podscripts.co's transcript archive: 1,268 episodes, ~109,000 timestamped segments, ~6,300 words per episode on average. spaCy's named-entity recognizer pulls every place-shaped string out of the transcripts: 26,091 candidate places, 109,414 (place, episode, timestamp) tuples.
2. Normalize & dedup
Raw NER output is messy. “Convert Garden”, “Cover Garden”, “Covenant Garden”, “the Covent Garden” and “Covent Garden” all show up as separate entries because the source is auto-transcribed audio. A fuzzy-merge pass collapses spelling variants, possessive forms, and transcription errors into 24,865 canonical clusters. Specific blocklists drop bare generics (“Castle”, “Park”), brand names, fictional places, and known noise.
3. Re-validate quotes
The original NER stored a 220-character context window per mention, but only ~62% of those windows actually contain the tagged place. So for each (canonical place, episode, timestamp), we open the original episode JSON and pull a wider ±2-segment window. We reject any appearance where the place name doesn't actually appear in that wider window. That filter validated 101,076 of 109,414 mentions.
4. Rank & pick the lead quote
Each canonical place is scored by log(validated count) × poi-multiplier × specificity-multiplier − rejection-penalty + landmark-bonus. Log-damped count keeps countries from dominating; specificity rewards multi-word names like “Covent Garden” over the one-word “London”. For each entry we then pick the single best validated appearance (longest fact-shaped sentence containing the place name, avoiding ad-read and intro patterns) and extract a single-sentence hook from that window.
5. Manual overrides
Pattern-based auto-drops catch lots of NER noise (acronyms, lowercase common nouns, newspaper suffixes, websites) but a small hand-curated place_overrides.json handles the named exceptions: drops for people that NER caught (Sean Connery, Napoleon, Indiana Jones), coord corrections for famously misgeocoded places (Eiffel Tower in Tennessee, Statue of Liberty in the Philippines), and a short list of fictional/space places that get pulled into the “Fictional & space” toggle.
Numbers
- 1,268 episodes parsed
- 109,414 raw place mentions extracted
- 24,865 canonical place clusters after dedup
- 101,076 mentions validated against a wider transcript window
- 2,050 entries on the live map after auto + manual cleanup
- 96 audited entries shown by default (Show favourites + Recurring)
What's still wrong
Plenty. The geocoder still misplaces some entries (Hamburger → Bremen, Mars → Mars-the-French-village, Natural History Museum → Oxford's rather than London's). The long tail of one-off mentions has unaudited NER survivors (concepts, eras, brands). Some extracted hooks start mid-sentence on episodes where the auto-transcript dropped sentence-final punctuation. Improvements ship as they're spotted.
Logbook
Every change to the map, newest first. New places are logged automatically as episodes are added; corrections and new features are noted here as they ship. Spotted something wrong? There's a feedback button on every place card.
- New episode mapped
3 new places added from the latest episode.
- New episode mapped
1 new place added from the latest episode.
- New episode mapped
1 new place added from the latest episode.
- White Cliffs of Dover: Isle of Wight (The Needles) -> White Cliffs of Dover, Kent
Fixed after a reader got in touch.
- Washington: Washington State (47.5, -120.5) -> Washington, D.C.
Fixed after a reader got in touch.
- White Mountains: Alaska (wrong) -> White Mountains, New Hampshire, USA
Fixed after a reader got in touch.
- Belvedere Palace: Vienna AT -> Cortile del Belvedere, Vatican City
Fixed after a reader got in touch.
- New episode mapped
3 new places added from the latest episode.
- New episode mapped
1 new place added from the latest episode.
- New episode mapped
2 new places added from the latest episode.
- New episode mapped
1 new place added from the latest episode.
- New episode mapped
2 new places added from the latest episode.
- Calton Hill, Edinburgh: pin name, fact text and Wikipedia panel all corrected
A reader spotted that the show's transcript mis-heard Calton Hill in Edinburgh as Carlton Hill, which had also pulled in the Wikipedia entry for a part of Brighton. The pin name, the fact text and the linked article now all point at the right hill.
- New episode mapped
2 new places added from the latest episode.
- Leeper -> Leiper in the fish_hook fact text
Fixed after a reader got in touch.
- Disputed fact notes now cover 30 pins
Where the show told a story that reality disagrees with, the pin now carries a note: the Bisley Boy legend, Princeton's 1927 April Fools hoax, the 10,000 (not 100,000) Tiananmen doves, London's first blue plaque (Byron, not Newton), and 25 more. The facts stay, faithfully as told on the show, with the record set straight underneath.
- Eleven pins moved to the right place after a full fact-check of every hook
An independent fact-check of all 2,012 map hooks (plus our own audit of every flag) caught eleven pins on the wrong same-named place. Fixed: Hoover Building (Perivale, not Ohio), Nikumaroro (Kiribati, not Antarctica), Duke of York's Theatre (London, not Australia), Wallis and Futuna, the Disappointment Islands (French Polynesia, not NZ), Salem (New Jersey, not Oregon), Matanzas (Cuba, home of the danzon), Smithfield and Stoke Newington (London), the Baltics (Estonia, not Ontario), and Oxford College merged into Oxford University.
- Mussels, not muscles
A reader gently flagged that the Rhino Party of Canada handed Belgium a case of mussels, not muscles. Fixed a transcription slip on the Montreal fact (and the same slip on a Great Lakes fact while we were at it).
- Heinz pin moved to the historic Heinz factory
The Heinz pin sat on the Senator John Heinz History Center. A reader pointed us to the original H. J. Heinz works on Pittsburgh's North Side (now the Heinz Lofts), a better home for the company's facts.
- Beach Road moved to Singapore
A reader spotted that the Beach Road fact (the beach it was named for vanished under reclaimed land) is about Beach Road in Singapore, not Beach Road near Perth. Repinned, with the right Wikipedia panel.
- New episode mapped
2 new places added from the latest episode.
- Facts the show got wrong now carry a 'Disputed fact' note
Some facts were reported on the show but do not hold up in reality. Rather than remove the pin (the show really did say it), these now carry a Disputed fact note explaining what reality says. First up: the Liechtenstein national stadium, which the show said straddles the Swiss border but actually sits wholly inside Liechtenstein.
- Royal Theatre moved from Canada to London
The Royal Theatre pin sat in Victoria, Canada. The fact is about Delpini's Don Juan pantomime, the one Byron said inspired his poem, staged at the Theatre Royal, Drury Lane in London's West End.
- Olympic Park moved from Russia to London
The Olympic Park pin sat in Sochi, Russia. The fact compares Tatlin's Tower to the tower at the Olympic Park, meaning the ArcelorMittal Orbit at Queen Elizabeth Olympic Park in London.
- Removed a misheard quote from Calgary
A quote on the Calgary page was actually about the world's first electric cargo ship. The transcript misheard 'cargo' as 'Calgary'.
- Fixed the Garibaldi biscuit fact on Nice
The Nice card wrongly merged two biscuits. Garibaldi, born in Nice, is the namesake of the Garibaldi biscuit (not the Nice biscuit).
- The Ritz moved from Finland to London
The Ritz was pinned in Finland. The fact (King Zog of Albania living there in exile) is about the Ritz Hotel on Piccadilly in London.
- Nassau moved to Baarle-Nassau, Netherlands
The Nassau pin sat in Germany, but the fact is about Baarle-Nassau, the Dutch enclave town whose name comes from the House of Nassau.
- Rheinpark Stadion moved to Liechtenstein
Liechtenstein's national stadium was wrongly pinned at Beijing's National Stadium (the Bird's Nest) because the bare name 'National Stadium' matched the wrong place. Now correctly in Vaduz, on the Rhine by the Swiss border.
- New episode mapped
2 new places added from the latest episode.
- Headquarters pins now explain themselves
When an organisation or brand is mentioned on the show (Greenpeace, NASA, Cadbury and the like), its pin sits at the headquarters. Those pins now carry a short note saying so, so nobody mistakes the head office for the place in the fact.
- The planets are now tappable
Our off-Earth pins (Mars, the Moon, Pluto and friends) were parked so far north they slipped past the top of the map and could not be clicked. Nudged them back into reach. Thanks to the reader who spotted the stray dot at the top.
- Booted a sponsor off the map
A reader flagged 'Ornod', which turned out to be a cycling-clothing brand from a Dutch-language advert read, not a place anyone talked about. Removed.
- Emerald Beach moved to the right hemisphere
A reader pointed out the Emerald Beach fact is about the town in New South Wales, Australia (a listener's home town), not the Emerald Beach in Missouri the pin had landed on. Fixed.
- Northern Cyprus pin: flag swapped for a plain island map
A reader with family displaced from the island asked us not to fly the TRNC flag on this pin. The flag image is replaced with a plain, unlabelled outline map of Cyprus. The fact and its context are unchanged.
- North and South Island now carry their Māori names
A reader asked us to honour the te reo names. Both islands are now dual-labelled, North Island (Te Ika-a-Māui) and South Island (Te Waka-a-Māui), the names the show itself gives in the Māui creation-myth fact.
- Wilmington moved to the right state
The banana-split origin fact is about Wilmington, Ohio, but the pin was on Wilmington, Delaware. Thanks to the reader who flagged it.
- Cape Ann sailed home from Antarctica
A reader spotted that the Cape Ann in the Benjamin Franklin lightning-rod fact is the one off Massachusetts, not the Antarctic cape the pin had drifted to. Moved it back to New England.
- Merged a doubled-up computing museum
The National Museum of Computing at Bletchley had accidentally become two pins, one stranded in Swindon. They're now a single pin in the right place.
- Stratford moved to London
A reader flagged the Stratford pin sitting in Connecticut. The headline fact is about Newham, the London borough, so it's back in the right Stratford.
- Perth Museum corrected to the WA Museum
The glory-hole fact is the Western Australian Museum (Boola Bardip) in Perth, Australia. The pin was right but the name and info panel still described Perth, Scotland. Both fixed.
- Mill Tavern moved to Cwmbran
A reader flagged that the Mill Tavern in the giant-vegetable fact is in Wales, not Surrey. It's now pinned in Cwmbran, where the National Giant Vegetable Championships began.
- Reading sent back to Berkshire
The transcripts heard 'Reading' as 'Redding', so those facts (including the live show and the cocoa quarantine centre) had drifted to Redding, Connecticut. Merged back into Reading, UK.
- Bluff Creek moved to California
A reader pointed out the Bigfoot filming spot (the Patterson-Gimlin site) was pinned in Ontario, Canada. It's now in the right Bluff Creek, in Northern California.
- Pinned some big rivers, seas and regions the show name-checked
Added representative pins for large features the transcripts had garbled, including the Congo and Yangtze rivers, the Aral and Bering seas, Lake Maracaibo, the Marco Polo Bridge and the Elysee Palace.
- More recovered places from the transcript sweep
A second verification pass rescued another batch of mis-heard spots, including Mont Donon, Murano, Mount Teide, the Forest of Dean, North Ronaldsay, Jokulsarlon and Kandy's Temple of the Tooth.
- Recovered 93 places the transcripts had mis-heard
After a reader flagged Lake Starnberg, we swept the archive for other places the auto-transcript had garbled so badly they never found a location (Isle of Wight heard as 'Isle of White', Lake Titicaca as 'Titikarca', RAF Lakenheath as 'Lake and Heath'). 93 of them are now correctly pinned.
- Added Lake Starnberg (Bavaria)
A reader spotted that Lake Starnberg, where King Ludwig II died, was missing. The transcript had mis-heard it as 'Lake Stranberg', so it never found a location. Now pinned in Bavaria.
- York University sent back to the right York
A re-check found the smell-historian fact pinned to York University in Toronto. Dr Will Tullett is at the University of York in England, so the pin has crossed the Atlantic home.
- Perth Museum moved to the right Perth
A reader spotted that the 'oldest glory hole in Australia' pin was sitting in Perth, Scotland. The fact is about Perth, Western Australia, so the pin has swum south to the correct hemisphere.
- Fixed four more reader-reported pins
Moved Madison Park to Madison Square Park in New York and the University of Keele grant fact back to Keele in Staffordshire, corrected a Burgess Hill quote, and pointed Brighton beach at the right Brighton. Thank you for the notes.
- Fixed 11 reader-reported pins
Moved 8 misplaced pins (incl. Whale Island to Portsmouth, Shark Bay to Safety Beach in Victoria, the Royal Military College to Sandhurst) and removed 3 that weren't really places, all from launch-day reader reports. Thank you for the corrections, keep them coming.
- Three pins put back where they belong
Listeners spotted them on day one: the Dolphin Tavern is back up in Holborn, the Hilton from the half-a-muffin letter is now in Istanbul, and the Brunel Museum has returned to Rotherhithe.
- Easier to tap a pin at the edge of the map
Pins near the edge of the map are now easier to click, and the fact card always opens fully in view instead of slipping off the side.
- The map went for a night swim
Every page moved onto a deep-water aquarium theme, so the pins and their facts sit on dark water rather than white paper.
- Other Worlds
The old off-Earth collection is now Other Worlds, with Mars, Venus, Pluto and the Moon tidied into one place you can actually explore.