The popular temporary slide attraction installed as part of a £1.2 million visitor improvement project at Framlingham Castle is set to remain until early October.
The so-called Time Tunnel slide opened in February, helping to attract about 5,000 visitors to the heritage property during the February half term week.
English Heritage is set to reveal the new additions of the project next month, including a new 40-seat café and an improved exhibition space.
Kirstie Horne, property manager at Framlingham Castle, said: “The slide has been so popular with visitors, both young and old. Now people will be able to enjoy it during May half term and throughout the summer holidays.”