Some of Scotland's most popular attractions have recorded a drop in visitors, prompting officials to call for more funding to be invested in tourism.

Visitor numbers fell at the National Gallery complex in Edinburgh and at the Scottish National Gallery of Modern Art, also in the capital.

Figures released by the Association of Leading Visitor Attractions (Alva) showed Edinburgh Castle was the only Scottish site to make it into the 20 most-visited in Britain last year. Visitors to the castle totalled 1,229,703 in 2007, a slight increase of 2%, while Stirling Castle remained static at just below 440,000.

The Falkirk Wheel proved popular with an increase of 18% which helped break it through the half a million mark, and Urquhart Castle on the banks of Loch Ness had a 12% increase to more than a quarter of a million.

However, visitors to the National Gallery of Scotland, the Scottish National Portrait Gallery and the Scottish National Gallery of Modern Art all fell with museum officials pointing to a hugely successful 2006 that was never likely to be repeated last year.

The figures cover only attractions which are members of Alva. Museums such as Glasgow's Kelvingrove and the Burrell are not included.

Peter Riddle, VisitScotland chief executive, said: "The Alva survey results are encouraging and demonstrate Scotland's main attractions continue to remain as popular as ever, with the likes of Edinburgh Castle and the National Museum of Scotland showing a rise in visitor numbers.

"Achieving the shared industry ambition to grow revenues from tourism by 50% by 2015 will require action from everyone involved in tourism, in both the private and public sectors."

He added: "The essential ingredients to achieve growth will be increased investment to expand the industry and greater productivity from within the industry."

His call was echoed by Robin Broke, director of Alva, who called on the UK government to provide more support to entice visitors from abroad.

He said other countries were "slowly but surely overtaking Britain as a destination". On cuts to funding, he added: "More seriously, it is preventing the nation's fifth-largest industry from optimising its potential earning power and creating significant numbers of new jobs."

Historic Scotland, which owns and runs many tourist attractions, including Edinburgh, Stirling and Urquhart castles, was pleased with the performance of its sites.

Peter Bromley, Historic Scotland director of properties in care, said: "The figures show that despite tough competition in the UK and overseas markets, and the fluctuating fortunes of the tourism industry, our properties rate as must-see destinations."