Scotland's historic sites have set record-breaking summer visitor numbers, with Edinburgh Castle topping the list.

The period from April to September 2017 saw a 20% increase in footfall on the same period last year, making it the busiest season on record, according to Historic Environment Scotland (HES).

The visitor numbers of more than 70 ticketed Historic Scotland visitor attractions were recorded including Edinburgh Castle, Iona Abbey and Fort George.

The busiest individual month was August, when more than 870,000 people flocked to historic sites.

The three most popular Historic Scotland paid-for attractions were Edinburgh Castle (1,433,896), Stirling Castle (430,405) and Urquhart Castle (405,388).

HES bosses say a further 13 sites have already exceeded their visitor totals for the last financial year.

The seasonal figures show sites continuing to benefit from the "Outlander effect" with places featured in the television series continuing to see large increases in visitor numbers.

Blackness Castle saw the most significant rise in visitors at 44%, followed by Doune Castle, used as the fictional Castle Leoch in the series, which recorded a 42% increase.

The figures were published as Scotland celebrates Heritage Awareness Day, dedicated to showcasing the country's diverse heritage.

Alex Paterson, chief executive of HES, said: "This year's summer season has surpassed our previous visitor records, as we welcomed over 3.8 million visitors to our historic sites across the country - an excellent 20% increase on last season's showing.

"We've responded to the increasing interest in Scotland's historic environment by extending opening at seasonal sites across the country throughout October, giving people further opportunity to explore the wealth of history that Scotland has to offer and to uncover the hidden historical gems on their doorstep.

"From Edinburgh Castle to Skara Brae, historic sites across Scotland are continuing to draw record numbers of visitors, which is further demonstration of the value of Scotland's historic places within the country's wider tourism offering."

Fiona Hyslop, Cabinet Secretary for Culture, Tourism and External Affairs, said: "Congratulations to Historic Environment Scotland on another great seasonal performance.

"As today's numbers confirm, Scotland's historic environment is acting more and more as a magnet for tourists, attracting millions of people from far and wide each year to our world class attractions.

"I am particularly pleased to be announcing this success as we celebrate the first-ever Heritage Awareness Day and as we approach the end of this Year of History, Heritage and Archaeology.

"The year has contributed to further enhancing the international profile of Scotland's intriguing history, impressive cultural heritage and fascinating archaeology."