A pic for context would help. And maybe a discussion of why so high above grade (not to redo, but to understand the style of house, if any landscaping, a sloped lot, etc). To cover it with siding or something similar, would probably need furred out, which may cause unwanted detailing where it meets the old house wall, but can be done. There are decorative products, like coated rigid insulation or "stick built" or panelized covers like thin brick/stone, or you can parge cementious products right to the concrete.

Will do Should be going to the cottage in the next few days