The 'pale pellucid green' of Lough Carra was remarked upon in 1906 by Ireland’s most famous botanist Robert Praeger. Things have changed since then due to nutrient enrichment. Photograph: Lynda Huxley

Two yellow brimstone butterflies led us down to the shore at the northeast end of Lough Carra in Co Mayo. As if on cue, the sun came out just as we re(...)