How is distance measured?

As the great-circle distance on a spherical Earth (radius 6,371 km) — the same way flight distances are calculated.

Which cities can it be?

Capital cities and cities over 3 million people, from Natural Earth's populated places. You can guess any city in the list.

800 points when found on the first try, 100 fewer for each extra try, 0 if not found.

Every day at 00:00 UTC. The countdown shows exactly when.

New puzzle in--:--:--

GlobeFor navigators, pilots and puzzle solvers

Position Fix turns trilateration — how GPS finds you — into a daily puzzle. Every ping is a clue; every circle narrows the map.

Tap anywhere on the globe and press Ping. A circle appears, coloured by how far away the city is.
Ping somewhere else: the city sits where the circles cross.
When you're sure, type the city's name and pick it. A wrong guess draws a circle from that city and uses a try.
Find it within seven tries; the fewer, the better.

Spread your first two pings far apart: circles that cross at a wide angle pin the city down faster.
Red circles are over 5,000 km away, green under 500 km.
A ping on the far side of the planet still helps: its circle is the mirror of a nearby one.

How is distance measured?: As the great-circle distance on a spherical Earth (radius 6,371 km) — the same way flight distances are calculated.
Which cities can it be?: Capital cities and cities over 3 million people, from Natural Earth's populated places. You can guess any city in the list.
How is it scored?: 800 points when found on the first try, 100 fewer for each extra try, 0 if not found.
When does a new puzzle come out?: Every day at 00:00 UTC. The countdown shows exactly when.