Historic Scotland has announced a record-breaking year with more than three million visitors to its sites.
Fort George is among Historic Scotland's more popular properties
Admission figures for ticketed properties in 2006-07 increased by 6% on the previous year.
Scotland's busiest attraction, Edinburgh Castle, rose by 2.7% with 1.2 million passing through the gates.
Culture Minister Patricia Ferguson will present the three millionth visitor to Historic Scotland's sites with a bottle of whisky.
A rise in admissions is also forecast at Linlithgow Palace in West Lothian (up 16.1%) and St Andrews Castle in Fife (up 18.3%).
It is estimated some of Historic Scotland's most popular attractions will have welcomed more than 3.1 million tourists by the end of the financial year later this month.
Ms Ferguson said: "This significant achievement underlines the importance of Scotland's rich historic environment, attracting visitors from all round the world.
"It comes during Scottish Tourism Week, when we celebrate the success of an industry that contributes so much to the nation's economic wellbeing."
The minister said tourism chiefs planned to boost revenues from the sector by 50% in the 10 years to 2015.
John Graham, Historic Scotland chief executive, said: "Our staff are always looking for new ways to encourage visitors to enjoy our attractions and I'd like to thank them for their outstanding efforts this year."
The agency has 345 properties in its care, including castles, abbeys, prehistoric settlements and lighthouses.
Stirling and Urquhart castles, Fort George, near Inverness, and Skara Brae in Orkney are among its most popular attractions.
Seventy-five of the sites charge an admission fee and 270 have free entry.