Ian Short

From 12 to 16 May 2025 I attended the workshop Frieze patterns in algebra, combinatorics and geometry at the Centre International de Rencontres Mathématiques in Luminy (near Marseille). I gave three talks on Frieze patterns and Farey complexes.

CIRM is located in Parc national des Calanques, a low mountainous region with rich botany and plenty of walking trails. On Wednesday afternoon, when no lectures were held, I set off on a circular walk over Mont Puget – which towers over Luminy – then on to the Mediterranean Sea and back. Here’s the route I took (clockwise).

CIRM is marked with a red cross. I had lunch among flowers and scrub before reaching the foot of Mont Puget.

The steep path up the final ascent of Mont Puget was my favourite part, with beautiful views.

Here’s another view; you can see some of the University of Aix-Marseille below, in which CIRM is based.

At the top I was delighted to see a scarce swallowtail. Swallowtails (of a different type) are rare in England but they are far from scarce in France. Still, for me it was a treat; I hadn’t observed them thus far on the walk.

One last look west before heading on.

I descended gradually towards the sea. There were flowers aplenty throughout the walk, such as love-in-a-mist.

Red valerian was in abundance.

This one is Montpellier rock rose.

The image below is of thyme growing out of a rock face (near Morgiou).

Lots more also – honeysuckle, hawkweed, cistaceae, and a purple flower we looked up called aphyllanthes, which is endemic to the region. I saw hundreds of lizards (which I couldn’t identify) and few birds. I heard serins in the trees and glimpsed them zipping around – again, these are rare in England. For butterflies, I recorded marbled whites, pale clouded yellows, painted ladies, and various others besides. Here’s a marbled white.

The path from Mont Puget headed east then south towards the sea, and then west. After a few kilometres I came to a gorgeous bay.

This bay is within relatively easy access of the Aix-Marseille campus, so it is frequented by students. I was tempted to stop, however, I’ve been there before, and I was keen to continue round the coast westwards towards the small village of Morgiou. There I finally got to have a swim in the small harbour.

Morgiou has a cafe/restaurant which had been recommended to me. With company I would have stopped there; on my own I chose to press on up and over Col de Sugiton and back to CIRM. From the top of the Col I took this picture of CIRM.