Pyrotachnics, giant mobile structures and haunting music will be brought together in two of the festival's most ambitious outdoor events.

But having an audience of up to 5,000 people does not come without its potential problems.

Health and safety, site locations and even the weather have to be taken into account when planning shows with such massive audiences.

Claire Raftery is co-artistic director of Periplum, the visual theatre group that will put on The Bell tonight and tomorrow at Wild Park, in Moulsecoomb, and Arquiem from May 16 to 18 at Brighton College, in Kemp Town.

Both are free and an audience of up to 5,000 is expected at The Bell and 1,000 to Arquiem.

Ms Raftery said: "The Bell is our most a m b i t i o u s production to date.

"It is site responsive so we really wanted to find the right site for it. We looked at lots of options but when we found Wild Park we felt that it had the right atmosphere.

"Moulsecoomb also has a strong community and it's a play about community."

The Bell tells the tale of a warring clan and features pyrotechnics from acclaimed pyrotechnic artists The World Famous. Before the show could go ahead both Periplum and The World Famous had to draw up risk assessments.

Ms Raftery said: "Our performers are doing a lot of close up action and there is quite a lot going on so it will be quite hectic."

The company of 19 performers and technicians have been planning the shows since September.

Students from Northbrook College and the University of Brighton as well as members of the public will also be volunteering to make sure things run smoothly.

At Brighton College the audience will move around to follow the action of Arquiem.

It is the first time the public school has held a festival event.

Ms Raftery said: "When we saw Brighton College we knew it would be absolutely perfect.

"It is obviously a working school, with students living there, but they have been very accommodating to us."

Arquiem is inspired by Browning's poem Porpyhria's Lover and the audience becomes a mob witnessing the execution of a boy who's murdered his love.

Organisers are hoping for good weather, as too much wind could cause problems for the performances.

Ms Raftery said: "If there is a little rain it will still go ahead, but wind is more of a problem.

"The performance would only ever stop if it became too dangerous for the performers or the public.

"But the weather forecast is good this weekend, so hopefully it will be fine."

The Bell begins at 10pm and Arquiem begins at 9.30pm.

For colour pictures of the event pick up your copy of The Argus on Monday.