Seven of Scotland's major tourist attractions welcomed over one million visitors last year, according to new research.

Edinburgh Castle topped the list with a total of 1,568,508 guests in 2015, while it was the only paid-for attraction to appear on the list.

The National Museum of Scotland in Edinburgh came out on top of the free attractions, clocking up 1,567,310 visitors over the course of the year.

The capital proved to be a source of great interest for visitors, also boasting the Scottish National Gallery and St Giles' Cathedral to give it four out of the seven most popular attractions in 2015.

Other well-trodden destinations included Glasgow's Riverside Museum and Kelvingrove Art Gallery and Museum, with Loch Lomond Shores in Balloch completing the list of sights to pass the one million mark.

The study, compiled by Glasgow Caledonian University, found that the top 10 attractions enjoyed a 5% increase in visitors last year, even after a strong previous year for tourism in Scotland, which saw it host the 2014 Commonwealth Games and Ryder Cup.

The Royal Botanic Garden Edinburgh, the Famous Blacksmiths Shop in Gretna Green, the Kelpies horse head sculptures and the Falkirk Wheel were also in the top 10 free attractions - all welcoming more than 600,000 people.

Popular sites demanding an entry fee included Edinburgh Zoo, Edinburgh Bus Tours and Stirling Castle, with Glasgow Science Centre and Urquhart Castle in Drumnadrochit also making the top ten.

The Royal Yacht Britannia and the Scotch Whisky Experience, both in Edinburgh, the Scottish Seabird Centre in North Berwick and Culzean Castle and Country Park in Ayrshire completed the top 10 paid-for list.

Professor John Lennon, director of the GCU's Moffat Centre for Travel and Tourism Business Development, said: "Scotland is clearly punching above its weight in visitor attraction performance.

"It is a testament to the range and appeal of Scotland's paid and unpaid offer that we continue to attract international and domestic tourists as well as local visitors to our visitor attractions."