It is estimated that over 10 years Eden will contribute �2bn to Cornwall

The attraction was visited by just over 1.4m people in 2003, down from 1.75m the year before.

It was the steepest drop of the UK's top 20 attractions, according to the Association of Leading Visitor Attractions.

But Eden remains in the top five of UK visitor attractions that charge for entry and in the top 10 overall and its bosses say they are happy with its performance.

Biome plans

Marketing director Dave Menneer, said: "Everyone tends to forget that Eden was built for 700,000 visitors, so we are operating at twice our business plan at the moment.

"We are comfortable with it from a business point of view and I think the visitors are comfortable with it because we do not have those lunatic days that we had a couple of years ago."

Eden unveiled plans last year for a third biome and education centre, but it is still �27m short of the �40m it needs.

The new biome would be next to the existing warm temperate biome and resemble the desert climate of Arizona.