Without the razzmatazz of the Tate or the Louvre, often quiet, frequently uncrowded, these unsung institutions contain a surprising quantity of world-class art. But what you see in the galleries is only about a fifth of what they actually own.

When you add to works in storage the publicly owned art to be found in unlikely places such hospitals, crematoria and schools, you realise there is a huge treasure-house of art that never gets seen.

Which is why the BBC's plan to make them all viewable online, in partnership with the Public Catalogue Foundation, deserves a warm welcome. The PCF has been beavering away at finding and cataloguing all these works, county by county, since 2004. Thanks to its efforts, we now know where to find a seascape by Noel Coward in Kent, or which paintings are owned by Leeds General Infirmary.

Then, of course, there are the masterpieces tucked away in unpretentious galleries around the country. The Bowes Museum outside Barnard Castle in County Durham, a reproduction French chateau on the slopes of the fells, contains, among many eclectic things, a fine group of Spanish paintings including Goya's Interior of a Prison. Even more surprising is to discover one of the finest large Tintorettos outside Venice in the Shipley Art Gallery, Gateshead.

York, Leeds and Sheffield all have fine art galleries with excellent arrays of British art, plus a sprinkling of fine non-British pictures. The Ferens Art Gallery at Hull harbours a hoard of Old Masters.

Liverpool is now one of the more important art towns in Britain, with the Tate Liverpool on Albert Dock plus the excellent Walker Art Gallery. The latter is one of the best in Britain - with a number of top-quality Old Masters, including works by Poussin, Rembrandt and Rubens. Manchester Art Gallery is strong in Pre-Raphaelites, while

the National Museum in Cardiff contains a wonderful collection of Impressionists, including no fewer than 10 Monets.

It is estimated that there are 300,000 publicly owned works of art in this country -- finally we may have a chance to see them all.