Admission charges were waived at sites on 20 November in 2007. This year the heritage organisation is opening up 47 attractions for free on 29 and 30 November.
Historic Scotland also announced recently that they are dropping admission prices to Edinburgh Castle from 1st November to 28th February to £10.00, while concession and child rates will drop to £7.00 and £5.00 respectively.
Looking beyond Edinburgh, among the attractions you can see on the free St Andrew's Day weekend are Stirling Castle, the historic Dunfermline Abbey and St Andrews Cathedral.
Romantic Sweetheart Abbey and medieval stronghold, Caverlaverock
Castle, are also included.
In the north, Orkney's ancient Skara Brae and Maeshowe will be taking part along with the Britain's mightiest artillery fortification, Fort George and the stunning Urquhart Castle. The fully furnished Blackhouse in the Western Isles will also be dropping admission charges.
A list of all the sites with free entry over the St Andrews Day
weekend will be posted on the Historic Scotland web site next week (see related links).
Historic Scotland's mission is to safeguard Scotland's historic environment and to promote its understanding and enjoyment. The organisation has 345 properties in its care, spanning over 5,000 years of history.
Rebecca Hamilton, marketing and media manager at Historic Scotland, said:
"We are delighted to offer free admission. Some of our country's best historic attractions are included making it an excellent opportunity for everyone to make the most of their St Andrews weekend. It is a chance to see Scotland's treasures such as the Scottish Crown Jewels and the Stone of Destiny at Edinburgh Castle. We can all feel immensely proud of our Scottish history - this is a chance to celebrate that. This is the first time Historic Scotland has opened up so many attractions for the full weekend to mark St Andrews Day."