Wakehurst Place, part of the Kew Gardens group, enjoyed soaring visitor numbers while most other attractions suffered an annus horribilis.
The Ardingly estate had the fifth highest increase in the country, according to the Association of Leading Visitor Attractions (ALVA).
Wakehurst is home to the Millennium Seed Bank project, which aims to save the world's most endangered plants from extinction.
The botanic gardens and seed bank exhibition saw a 20 per cent increase in visitors year-on-year to 389,396 in 2003.
Andy Jackson, head of Wakehurst Place, said a "stunning autumn", which included a record 5,000 visitors on a single day in October, had helped.
He said: "To be able to repeat this amazing figure would be unlikely.
"The weather and conditions were all in our favour last year, from a wonderful spring and stunning summer to the best autumn many can remember.
The gardens looked a picture the whole time."
A new entrance opens on March 25, housing a coffee shop, plant sales area, gift shop, reception and admissions and information areas.
Meanwhile, prospects for Britain's inbound tourism industry as a whole are picking up, new figures indicate.
The British Incoming Tourist Association (BITOA) says the foreign tourist market is beginning to boom again after a difficult 2003.
The number of overseas visitor arrivals in December 2003 was 5.4 per cent up on December 2002 and the best since January 2003.
Forward bookings in December 2003 were up 7.3 per cent.
The association's chief executive, Stephen Dowd, said: "The promise of recent months would seem to have been delivered in December.
"All sectors reported increased visitor numbers and there were hints the pressure on rates is easing slightly.
"The best news was that growth was spread across all markets despite worries about the weakness of the US dollar.
"Strong forward bookings also generated some festive cheer.
"Prospects for 2004 continue to look more positive, with members from all sectors reporting increased inquiries and bookings."
Like everywhere in the country, Sussex has suffered a gradual decline in visitor numbers in recent years with negative repercussions for business.
The respective economic partnerships have been working with East and West Sussex County Council and Brighton and Hove City Council to reverse the trend.
Friday February 20, 2004
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