Seven Scottish tourist attractions recorded more than one million visitors last year, according to new research.

Edinburgh Castle was the only paid-for attraction on the list and achieved the most visitors, with 1,568,508 people passing through in 2015 - making it the most popular overall.

The others, including Glasgow's Riverside Museum and Kelvingrove Art Gallery and Museum as well as the Scottish National Gallery in Edinburgh, are free to visit.

The National Museum of Scotland in the capital was the top free attraction, with 1,567,310 visitors.

The city's St Giles' Cathedral and Loch Lomond Shores in Balloch make up the remaining sites to pass the one million mark in the study by Glasgow Caledonian University (GCU).

Researchers at the Moffat Centre for Travel and Tourism Business Development found visits to the top 10 attractions increased by 5% in 2015, which followed a strong 2014 after Scotland hosted events such as the Commonwealth Games and the Ryder Cup.

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

Other top paid-for sites included Edinburgh Zoo, Edinburgh Bus Tours and Stirling Castle, Glasgow Science Centre and Urquhart Castle in Drumnadrochit.

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 centre, 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."