| Accreditation | Unaccredited |
| Admin_hierarchy | /Isle of Man |
| DOMUS_Subject_Matter | archaeology |
| DOMUS_identifier | 927 |
| Governance | Independent-Unknown |
| Identifier_used_in_source_database | NW000156 |
| Latitude | 54.06423 |
| Longitude | -4.62302 |
| Name_of_museum | St Marys Chapel, The Old Grammar School |
| Notes_internal | if we include this, do we include historic churches, e.g. CCT? |
| Postcode | IM9 1RE |
| Primary_provenance_of_data | domus |
| Size | medium |
| Size_prov | domus |
| Subject_Matter | Buildings-School |
| Town_or_City | Castletown |
| Visitor_Numbers_Data | 3:26470:1998:domus |
| Year_closed | 9999:9999 |
| Year_opened | 1951:1951 |
| Year_opened_source | dfoundation |
| media | 0 |
| project_id | mm.domus.NW156 |