The 30 museums on the long list for the 2009 Guardian Family Friendly Award include Beningbrough Hall in York, the Highland Folk Museum in Newtonmore and the Great North Museum.
A final six, drawn up by a panel chaired by Jenny Abramsky, chairwoman of the Heritage Lottery Fund, will be unveiled next month.
The prize, which is run by the Kids in Museums charity, will be judged by families and children, and the winner will be announced in April.
The winner will receive 500 Mammoth Activity Sheets, donated by design company Foldedsheet.