| 1 Treseifion, Caergybi, Ynys Mon | - | 87 m² | - |
| 2 Treseifion Estate, Holyhead | Freehold | 85 m² | £118,000 (2024) |
| 3, Treseifion Estate, Holyhead | Freehold | 87 m² | £41,500 (2000) |
| 4, Treseifion Estate, Holyhead | Freehold | 85 m² | £89,950 (2020) |
| 5 Treseifion Estate, Holyhead | Freehold | 90 m² | £135,000 (2022) |
| 6, Treseifion Estate, Holyhead | - | 95 m² | - |
| 7 Treseifion, Caergybi, Ynys Mon | - | 88 m² | - |
| 8 Treseifion, Caergybi, Ynys Mon | - | 84 m² | - |
| 9, Treseifion Estate, Holyhead | Freehold | 87 m² | £115,000 (2021) |
| 10 Treseifion, Caergybi, Ynys Mon | - | 85 m² | - |
| 11, Treseifion Estate, Holyhead | - | 93 m² | - |
| 12 Treseifion Estate, Holyhead | Freehold | 103 m² | £129,000 (2016) |
| 27, Treseifion Estate, Holyhead | - | 82 m² | - |
| 27A, Treseifion Estate, Holyhead | - | 82 m² | - |
| 28, Treseifion Estate, Holyhead | - | 71 m² | - |
| 28A, Treseifion Estate, Holyhead | - | 72 m² | - |
| 29, Treseifion Estate, Holyhead | - | 69 m² | - |
| 29A, Treseifion Estate, Holyhead | Leasehold | 70 m² | £64,000 (2019) |
| 30, Treseifion Estate, Holyhead | - | 71 m² | - |
| 30A, Treseifion Estate, Holyhead | - | 71 m² | - |
| 31, Treseifion Estate, Holyhead | Leasehold | 69 m² | £69,950 (2007) |
| 31A, Treseifion Estate, Holyhead | - | 71 m² | - |
| 33, Treseifion Estate, Holyhead | Freehold | 87 m² | £93,500 (2016) |
| 34, Treseifion Estate, Holyhead | - | 89 m² | - |
| 35, Treseifion Estate, Holyhead | Freehold | 88 m² | £123,000 (2014) |
| 36, Treseifion Estate, Holyhead | - | 92 m² | - |
| 37, Treseifion Estate, Holyhead | Freehold | 93 m² | £138,000 (2024) |
| 38, Treseifion Estate, Holyhead | Freehold | 86 m² | £75,000 (2011) |
| 39, Treseifion Estate, Holyhead | - | 84 m² | - |
| 40, Treseifion Estate, Holyhead | - | 84 m² | - |
| 41, Treseifion Estate, Holyhead | - | 74 m² | - |
| 42, Treseifion Estate, Holyhead | - | 74 m² | - |
| 43, Treseifion Estate, Holyhead | - | 74 m² | - |
| 44 Treseifion Estate, Holyhead | Freehold | 79 m² | £66,000 (2026) |
| 45, Treseifion Estate, Holyhead | Freehold | 76 m² | £72,000 (2015) |
| 46, Treseifion Estate, Holyhead | Freehold | 88 m² | £84,000 (2006) |
| 48, Treseifion Estate, Holyhead | - | 92 m² | - |
| 50, Treseifion Estate, Holyhead | - | 129 m² | - |
| 51, Treseifion Estate, Holyhead | - | 123 m² | - |
| 52 Treseifion Estate, Holyhead | Freehold | 92 m² | £95,000 (2014) |
| 53, Treseifion Estate, Holyhead | - | 96 m² | - |
| 54, Treseifion Estate, Holyhead | - | 92 m² | - |
| 55, Treseifion Estate, Holyhead | - | 96 m² | - |
| 56, Treseifion Estate, Holyhead | Freehold | 97 m² | £80,000 (2014) |
| 57, Treseifion Estate, Holyhead | - | 96 m² | - |
| 59, Treseifion Estate, Holyhead | - | 84 m² | - |
| 61 Treseifion, Holyhead, Holyhead | Freehold | 84 m² | £35,000 (2003) |
| 62, Treseifion Estate, Holyhead | - | 72 m² | - |
| 63 Treseifion Estate, Holyhead | - | 76 m² | - |
| 64, Treseifion Estate, Holyhead | - | 74 m² | - |
| 65 Treseifion Estate, Holyhead | - | 92 m² | - |
| 66, Treseifion Estate, Holyhead | - | 74 m² | - |
| 67 Treseifion Estate, Holyhead | - | 77 m² | - |
| 68, Treseifion Estate, Holyhead | - | 74 m² | - |
| 69, Treseifion Estate, Holyhead | - | 79 m² | - |
| 70, Treseifion Estate, Holyhead | - | 72 m² | - |
| Argraig, Treseifion Estate, Holyhead | - | 120 m² | - |
