Sisley in England and Wales, National Gallery, London

Many think of him as a minor French Impressionist. In fact, though born in Paris, Sisley was christened Alfred, and his parents were both British.

Few Sisley shows have been quite as small, pernickety and pleasurable as this one. The Sunley Room has even been reduced in size – and why not concentrate on something rather small and jewel-like for a change?

Most of the paintings – there are just 16 in the show – are modest in scale (well, when you are painting out of doors, as so many of the Impressionists so often did, you have to bear in mind the possibility of your canvases being buffeted by the wind) and show us the works Sisley did when he came to England. There were just a few visits, and they were quite well spaced out.

Half of the show is devoted to one poignantly glorious year, 1897, when Sisley and his mistress finally decided to do the right thing at Cardiff Town Hall and then made a little vacation out of the occasion. They stayed in Penarth, beside the sea, and Sisley painted what he saw. Then he looked out of the window from the Osborne Hotel, and painted exactly what he saw there too.

These few paintings represent a tremendously lightsome, fairly stylistically reckless late flowering of sea-cum-landscapes – he manages to squeeze in a bit of both in most of them. Look at The Wave, Lady's Cove, Langland Bay; an elegantly regulated firework display of water is bursting back from the rock. The entire scene is full of theatrical artifice, which includes a superabundance of white highlights. By the end of the year Sisley was dead, of throat cancer.

Much earlier in his life he had painted England, the banks and bridges of the Thames, and around Hampton Court, though he wasn't at all interested in the pomp and splendour of the palace itself. That sort of thing didn't catch his eye. What enthralled him were the undersides of bridges, their solidity, their indomitability. That feels like a bit of Britishness manifesting itself. He also liked splashes of pageantry on the river too – flecks of dancing light, gaily streaming pennants.

Sisley wasn't very successful at painting from a commercial point of view, even though he showed with the other Impressionists in that first, great Paris show of 1874. Two of the paintings in this show date from 1880, and they were made in France – Sisley painting in the high Impressionist manner, all shimmery light and tremulously full detail, and they are undeniably lovely.

To 15 February (020-7747 2885)