On a recent trip to Europe, I visited a beautiful gothic abbey. Walking up the dark aisle between old wooden pews, the air heavy with the odour of incense, I could only marvel at the beautiful stained glass windows illuminating parts of the massive stone church with their vibrant light, and espec...

I've recently returned from a week of travelling around Europe, visiting a different town or city in a different country on each day, choosing my destinations according to an underlying pattern. I've plotted the first six places I visited on the map below; I need you to tell me: Which UK town or ...

You have a straight line $l$ in an infinite plain. You can fold the plain along any straight line so the line $l$ becomes two rays with a common starting point. In the picture we fold along line $a_1$ to get the shape that is composed of the red ray $AB$ and the blue ray $AE$ You can fold the pl...

Inspired by this puzzle, I created (or discovered) these grids. Within each Boggle board is a set of words with a common theme. To make a word in Boggle, connect at least three letters horizontally, vertically, or diagonally, without using the same letter twice. Some of these grids contain blanks...

What are ten smallest natural numbers n, such that n and n+1 have digital sums which are not relatively prime?

This is an acrostic puzzle which uses cryptic clues. If you're unfamiliar with either or both of those, click the associated link. A complete answer should give the quote, author and source, as well as solutions and explanations of the cryptic clues. Oh, and in case you're too lazy to solve this ...

I'm considering an $2k\times 2k$ square grid ($k\in\mathbb Z^+$) with $8k$ highly rational people standing along the vertices forming the perimeter. All of these people want to go to the centre of the square. Within unit time, each person can either decide to stay on their vertex or walk to an ad...