Free attractions

There are many excellent tourist attractions which offer free admission- naturally they invite visitors to make a donation- but even with a modest donation, they can save you (especially if you have children) substantially: examples are: National Rail Museum York, National Media Museum Bradford, Ashmolean Museum Oxford, Pitt Rivers Museum Oxford, Fitzwilliam Museum Cambridge, Scott Polar Institute Cambridge, Norfolk and Suffolk Aircraft Museum Flixton (near Bungay Suffolk))... some other  museums have free entry 'out of season'.