Doune Castle appears as Castle Anthrax in the 1970s film

The 14th Century keep was made famous as Castle Anthrax in the 1975 classic film Monty Python and the Holy Grail.

Tickets have been restricted to 500 for the event near Stirling, which sees fans taking to the castle's battlements to enact scenes from the famous film.

Aficionados will also have the chance to take part in the coconut conga or the Python Idle talent contest.

The first Monty Python Day was held at Doune Castle, six miles north-west of Stirling, in 2005 to mark the 30th anniversary of film.

The film provided the inspiration for the hit musical Spamalot

Pilgrims attending this year's event are being promised a few surprises from organisers.

Nick Finnigan, Historic Scotland events and filming manager said: "The event has been a sell-out for each of the past three years and this year has been no exception, with all 500 tickets snapped up weeks in advance.

"As well as all the old favourites, we have introduced some special new activities to the line-up including a Monty Python Hall of Fame featuring photos from past Python events.

"There will also be a few surprises on the day itself."