Yes, your shed does need a base. This is to give it a solid, level foundation. Open soil will not help with the longevity of the shed itself or the contents within. The best materials to use to make your shed base are concrete, natural stone or wood.
Newtonmore
Newtonmore is a town in the Highland council location of Scotland. The town is just a few miles from an area that is asserted to be the specific geographical centre of Scotland. The town is house to The Wildcat Experience - a visitor attraction particularly targeted at households with children. The attraction is based on a neighborhood arts task - everyone in the town had the chance to be involved. Newtonmore is the site of the Highland Folk Museum.