Welcome to 100 Hours 2025
It looks like you aren't in the UK or Ireland ... that's ok!
Just be aware that you may see things in a different place in the sky. And if you are on the equator or in the southern hemisphere, you will probably not be able to complete all the challenges.
If you take part, please set your location as "Not UK or Ireland". We would love to know how many people are joining in from other countries.
First choose a marker and search for your location
This marker will be added to your pin when you complete challenges