Warning! Full interview contains S5 spoilers
From Radio Times:
Merlin: Colin Morgan answers YOUR questions on Doctor Who, plans for the future and juggling What’s your favourite memory of working on the show?
It’s probably my very first day - you know, being on set and that excitement and uncertainty, and the expectation of what was to come. It was just a huge adventure and I very much look back on that time as being very exciting. It was the beginning of an era.