Hertford Carnival 2017 Carnival at the Castle! Hertford Carnival will be taking place on Sunday 25th June, where Isabel Hospice has been chosen as a beneficiary charity for the event. Stalls and entertainment will be taking place at the Castle from 12-5pm, with various other events around the town. For more details, visit the Hertford Carnival website, including how to get involved as a stall-holder or volunteer, and - just prior to the day - the full listing of events and participants. We hope to see you there!