It's great at the Tate, yeah

Tate Director Sir Nicholas Serota has already imagined next year's headlines - Attendances at Tate Modern slump: honeymoon over for London's wonder gallery. It is that degree of foresight which goes some way towards explaining why London's first museum of modern art, which will celebrate its first anniversary next Thursday, has been such an extraordinary success.

Working for seven years on the project in close conjunction with all interested parties, Sir Nicholas managed to avoid all the pitfalls, even emerging from a fly-on-the-wall television documentary with reputation intact. Now, having foreseen the possibility of a downturn in attendances, the man most responsible for the arrival on Bankside of this £135 million phenomenon is clear about what is needed.

"We are bound to have a reduction in numbers," he says. "The principal challenge now is going to be to make the exhibitions that people expect to be there - and expectations are very high, namely that Tate Modern will deliver some memorable shows."

In this regard he is placing great faith in this autumn's big exhibition on Surrealism, the first in London in more than 20 years, and before that on Zero to Infinity: Arte Povera, the first major exhibition in this country to examine the work of the Italian precursors in the 1960s of conceptual art.

If there has been a downside to the arrival of Tate Modern it is in the critical reaction not to the building - its magical transformation from power station to gallery has been universally acclaimed - but to its contents and particularly how they are shown.

The Tate's decision to display its collection of modern art by arbitrarily chosen themes rather than chronologically has attracted much flak and its first attempt at a blockbuster show, Century City, was panned. The Serota response gives little away. "When you do something novel you expect people to be surprised, you expect people to react," he says.

But in numbers alone, Tate Modern's success has been spectacular. When the final figures are published, they will show that more than five million people visited London's first museum of modern art, compared with The Dome's 6.5 million.

The popularity of Tate Modern came as a shock. "We projected we would get 2.5 million visitors," Sir Nicholas recalls. His projections for the old Tate, rebranded as Tate Britain, were nearer the mark: attendances have dropped to 1.2 million from the 1.8 million who flocked the previous year to the then Tate Gallery. "It did not surprise me," he says. "If you are in London for a couple of days and you have the choice between going to the new Tate Modern or Tate Britain, then you go to Tate Modern.

"But with the advent of exhibitions like the Blake and Spencer and with the opening in November of our centenary development, we will see a return [at Tate Britain] to the numbers we had before."

Initially Bankside had problems with the sheer unexpected weight of numbers. There were long queues both outside the museum and inside, especially for the cafe and restaurant. "The queue moves much quicker now," says Sir Nicholas, 55. "The costs of servicing the building have increased, but fortunately we have been able to absorb them. The extra £5 million we received from government represents less than half the cost of running Tate Modern.