Show Scotland, co-ordinated by the Scottish Museums Council, will take place at venues from the Borders to the Highlands and Islands with events for all ages.
In Aberdeen, the Art Gallery is running Me, Myself and I, where visitors can explore their identity by designing a personal flag, bank note and tartan. In the city's 17th-century Tolbooth prison on Satur-day, members of the public will be randomly "arrested" by the gaoler and locked up with two prisoners from the past who will describe the conditions they had to endure.
At the Almond Valley Heritage Trust in Livingston, sausage making, pudding races and haggis hunting are on offer in a celebration of West Lothian's food heritage.
Visitors boarding the "Discovery" in Dundee can learn what life was like for the ship's crew in the old days, through music, song, storytelling and craft activities. At the Scottish Maritime Museum in Irvine, there will be "castaway" sessions involving raft building and other ways to escape from a desert island.
After-hours events are being held at a number of venues including Kelvingrove in Glasgow when, tonight, a "Scottish Night at the Museum", inspired by the 2006 Hollywood film, will feature music, drama and dance - and statues coming to life.
Also tonight, at Low Parks Museum in Hamilton, is the intriguingly titled Oh My Poor Nerves!, described as a performance and display of "health and hypochondria in the age of Jane Austen".