The biggest horseracing yard in the country opens its stable doors to the public tomorrow with an open morning to raise money for charity.

It is an event that offers a fascinating insight in to the life of a major racing stable. And they don't come any bigger or more successful than Castle Stables at Arundel.

The yard is the home of flat racing's leading trainer John Dunlop and it is where he looks after some 200 of the most valuable and expensively-bred thoroughbreds in the world.

From 10am to 1pm, about 130 of them will be on show, ranging from successful stars like St Leger winner Millenary to potential stars among a whole host of unraced two-year-olds.

This year's potential Classic horses like Silver Grey Lady, Olden Times and Time Away will be there while some of the country's best older horses, including Lucido, Right Wing and Romantic Affair are still stabled at Arundel.

Castle Stables also houses the best team of staying horses in the country with Orchestra Stall, Golden Snake, San Sebastian and Samsaam all competing for top honours this season.

Two charities are to benefit from the open morning, Racing Welfare, the longstanding horseracing charity for retired racing staff, and the Chestnut Tree House Appeal.

This is based at Worthing and is fundraising to build a hospice for children with life-threatening illnesses.

The biannual Open Mornings at Castle Stables have been running since the Eighties and are now a regular feature on the racing calendar.

They used to be very much for the die-hard racing fan but nowadays it is more families and the general public who mingle among the stable staff and their charges at Arundel.

As a result there are also a host of side shows including roundabouts, stalls and raffles to keep visitors entertained.

But the horses are the undoubted star attraction and they are one of the strongest collections of thoroughbreds in the world.

Admission costs £5 with a reduced entry fee of £1 for senior citizens and children under 12 years old.