ENGLISH Heritage is unlocking the key to the turbulent events of the Civil War tomorrow, as part of its contribution to National Archaeology Day.

The organisation's major warehouse in the North - located in Helmsley, North Yorkshire, is normally off limits to visitors but will open its doors to young history buffs to reveal the vast amount of 17th Century weaponry that has been recovered from the town's 800-year-old fortress.

Helmsley Castle was subjected to a three-month siege by Parliamentary forces under the command of Sir Thomas Fairfax in the autumn of 1644.

The Royalist garrison eventually capitulated, but marched out defiantly with their colours flying.

Tomorrow, curators will be displaying period swords, cannon balls and shot, along with everyday objects such as drinking vessels and branding irons.

In the afternoon, the action moves to Helmsley Castle for a guided tour of the ruins.

Both events are aimed at children over seven, who must be accompanied by an adult.

Admission to the event is free, but booking is required and can be made on (01904) 601901.