It is hoped opening Castle Cornet earlier than usual can help boost tourism in Guernsey.
The attraction will open on Friday 17th February to coincide with the half-term break.
Initially it will be open from 10am to 3pm seven days a week. All its five museums and shop will be open, but initially not the café, tours or noonday gun.
It is as part of Visit Guernsey’s drive to increase tourism revenue by £14.8 million and visitor numbers by 10%.