by Jonathan Morris
BBC News Online Cornwall
Plans for a giant third greenhouse at the Eden Project are going on display.
The Eden Project drew 1.3m people in its first year
The dry tropics biome is part of a £75m development which will also include an education building, field centre and student training facilities.
The geodesic biome is planned to open in 2005, next to the kilometre-long complex of humid tropics and warm temperate biomes.
The plans will be at the Engine House in Aylmer Square, St Austell from this week.
Planning permission for the latest developments is expected to be sought in the spring.
European funding is being sought for the latest addition to Eden, which is already Britain's third most visited attraction.
The £86m Eden Project, opened in a clay pit near St Austell in 2001, drew 1.3 million people in its first year.
It has been estimated that over the coming decade, Eden will contribute £2bn to Cornwall's economy.
Eden Project's media director, Paul Travers, said the point of the new biome is not to attract more visitors, when asked about concerns over possible increases in numbers.
He said: "In 1996 when the scheme was first conceived, it included three biomes.
"We didn't dare dream that we would get more than 750,000 people. Now we are getting close to 2m a year.
"But it is not about attracting more visitors, it is about making their visit more enjoyable, more comfortable, not just for visitors, but also for the team that work with us here."
The biomes - the largest of which could house the Tower of London - house conservatories with plants from round the world.
Boardwalks lead visitors through 12,000 plants, taking them from the Oceanic Islands to Malaysia and from West Africa to South America.