Treasure Map Japan

How to read the map, how to filter it, how packs are sold, and how to use the app offline.

The four tabs

“Map” tab

See the candidate sites on the map. “Legend”, at the top left, explains what the colors, shapes, sizes and lines mean.

“Packs” tab

Browse the areas in the app as a list. This is also where you buy them.

“My List” tab

The packs you starred and your notes for each site are collected here.

“Settings” tab

Holds this guide, the rules and disclaimer, restoring purchases, the language setting and outdoor mode.

You can open this page from “Settings” at any time.

How to read the map

Color = mineral

The color tells you which stone the site is a candidate for.

Size = rank

The bigger the mark, the higher the spot ranks by that pack's own measure (Rank A / B / C). Each pack uses a different measure, stated in its details. It is not a field-checked ranking of how likely you are to find something, and it does not guarantee any find.

Shape = type of place

● gravel surface, ◎ loose-boulder surface and ■ exposed rock are surfaces you actually collect from. ▽ is an “entry way-marker”, not the collecting spot itself.

Line = section to search

Solid line = a stretch confirmed from data to be riverbed, beach or outcrop. Dashed line = a candidate stretch (check on site before searching).

The same information is in “Legend”, at the top left of the map — quicker to reach when you are out in the field.

A point, or a stretch

Placer gold and platinum: a point

Their density is in another league, so in a river they tend to collect on the inside of bends and in cracks in the bedrock. The dots on the map are "way-markers to the river" placed at spots with that shape; nobody has confirmed that the dot itself is where they collect. Once there, pick point bars and rock cracks yourself along the stretch around it.

Other minerals: a stretch

Their density is much like the surrounding stones, so they do not pile up in one spot. Anywhere along the stretch drawn as a line is possible.

Line thickness means the same as mark size

The thicker the line, the higher its rank — and the bigger the marks that sit on it.

What decides it is not river versus coast, but whether the mineral is heavier than the stones around it.

Filtering and search

Filter by mineral

The bar at the bottom of the map toggles minerals and experience sites. It is quickest to tap “Hide all” once and then bring back only what you want to see.

Filter by “Access”

There are four: “Easy access”, “Short walk”, “Difficult terrain” and “Unknown”. “Unknown” means no road data reached the site — not that you cannot get there.

Switch the season

On the coast, longshore drift reverses with the season, so the shading changes with it. The default is today’s season; “Now” takes you back to it.

Search by place name

Type a place name, a pack name or a river name into the search field on the map. You can also pan to places the app does not cover.

To undo all filters at once, use “Show all map layers again” in “Settings”.

Free to use

17 packs open for free

Candidate sites, the reasoning behind them and the note-taking all work exactly as in a paid pack. You can try the stretch (line) display here too.

27 experience sites & sanctioned spots

Their locations are public information, so they are included free. If this is your first time, learning the technique at a site like these is the surest start.

The “Mineral guide” is free too

How to tell stones apart, the varieties and the shark-tooth species are all free to read.

Records of places where nothing was found are published free of charge too, as research notes.

How packs are sold

113 paid packs

17 kinds of minerals and fossils are covered. Open the pack for the area you want from the “Packs” tab, or from a locked mark on the map.

One purchase opens all of it

For packs that bundle several localities or rivers, a single purchase puts every area inside them on the map. They are not sold area by area.

Bundles

Region-wide and all-in bundles cost less than buying the parts separately. Switching to a bundle after buying single packs does not refund the difference, so take a look at them first.

One-time purchase, restorable

There is no subscription and no further charges. After changing device or reinstalling, use “Restore Purchases” in “Settings” (sign in with the same Apple ID you bought with).

The price shown in the App Store is the authoritative one. The free packs and the guide work without any purchase.

Keeping notes in “My List”

★ = the “Interested” mark

Star a pack on its detail page and it gathers in “My List”, along with what the starred packs would cost bought singly and which bundle contains them.

“Want to go”, “Visited”, “Found it!”

You can record these for each site in a pack you have unlocked.

Your notes stay on the device

Neither your notes nor your location are sent anywhere. The developer cannot see them.

If you get color in the field, send us the site ID and a photo from the report button on the site details. It becomes material for the next version.

Prepare with the “Mineral guide”

Looks, how to tell them apart, common look-alikes

For each mineral, the tests you can actually do in the field and the things people most often mistake it for.

Varieties and shark-tooth species

You can also look up the color variants of agate and garnet, and the shark-tooth species found on Japanese beaches.

Open it straight from a pack

From “What you can find here” on a pack’s detail page, you can jump to that stone in the guide.

The same common name can cover different species and epochs depending on the locality. Reading this once before you set out changes which stones you pick up.

Read before you go

Sites that “may be in breach” are not hidden

Natural-monument zones and places that need permission stay in the map, with the conditions spelled out. The only sites removed are those you physically cannot stand on.

“Read before you go (laws and hazards)”, before unlocking

Unlocking a paid pack always takes you through a page on the local rules and hazards.

Open “The 3 rules & disclaimer”

Play only where you are allowed in; leave it fit to play in next time; never underestimate nature. You can read them from “Settings”.

Candidate sites are only candidates. Who manages access and collecting differs from place to place, so please confirm for yourself before you set out.

Using it out of signal range

Sites show even out of range

Candidate sites, the reasoning and your notes all run on data held on the device. Only the map background needs a connection.

Load the map before you leave

Coverage is patchy in the mountains, so it pays to display the area you are heading for once and let the background load.

Take them out with “Export GPX (for GPS apps)”

From a pack’s detail page you can take the sites over to a hiking GPS app.

Only the map background you have already displayed stays on the device.