From alpinist/physicist John Tyndall's "Expedition of 1856" to the Bernese Oberland:-
We descended to the glacier and proceeded towards its source. As we advanced an unusual light fell upon the mountains, and looking upwards we saw a series of coloured rings, drawn like a vivid circular rainbow quite round the sun. Between the orb and us spread a thin veil of cloud on which the circles were painted; the western side of the veil soon melted away, and with it the colours, but the eastern half remained a quarter of an hour longer, and then in its turn disappeared."
Sun haloes and sun dogs can be seen anywhere in the world, but they seem to be especially frequent in the Bernese Oberland. Often they are associated with the veil clouds that come in ahead of a warm front. Here are two from this spring.
Bächlital, April, with circumzenithal arc at the top of the picture
Tyndall quotation from John Tyndall, The Glaciers of the Alps & Mountaineering in 1861, published by Everyman, 1906, reprinted 1911
Related post: Marcel Minnaert's Light and Colour in the Outdoors