Guernsey's most famous Castle, Castle Cornet has stood guard over St Peter Port's Harbour for 800 years. Built in 1202 to defend what was once a busy trading harbour, it remains surrounded by the sea, a short walk from the town centre with spectacular panoramic views of St Peter Port and out across to the other Channel Islands
Castle Cornet, listed as a Protected Monument in the late 1930's, is a museum in itself, and one that also houses five museums within its ancient walls.
| Date of Issue | 4 May 2017 |
| Designer | Two Degrees North |
| Printer | Cartor Security Printing |
| Values | 44p, 59p, 60p, 73p, 80p, 90p |
| Process | Offset Lithography |
| Stamp Size | 38mm deep x 38mm wide |
| Paper | 110gsm umwatermarked PVA Adhesive |
| Perforation | 13.75 x 14.75 |
| Cylinder | A |