A good example of the use of "The" is this search
The "Longstone" standing stone near the top of the list is NOT actually "The Longstone", but simply a standing stone in a townland called "Longstone". There are, however, many stones called "The Longstone".
When a site has a proper name I think the "The" should be used.
Do we adopt the proper listing protocol of using "Swastika Stone, The" ? or at least ask the birthday boy list them that way?