All locations except Knepp Wildland can be found by visiting nationaltrust.org.uk.
Knepp Wildland, New Barn Farm, near Horsham, West Sussex Rewilded farmland and now a hotspot in July for the Purple Emperor and White Admiral (above); August for the Brown Hairstreak. Public footpaths cross the estate or visitors can go glamping on...
Murlough Dunes, Dundrum, County Down The flowery sand dunes are excellent for butterflies and Murlough is home to the Cryptic Wood White (not found on the British mainland) and the beautiful Marsh Fritillary.
Arnside Knott, Arnside, Cumbria Beautiful National Trust reserve overlooking Morecambe Bay. Stronghold for the Grayling (above) and the rare High Brown Fritillary; most southerly site in Britain for the Scotch Argus.
Box Hill, Surrey Visit this North Downs site in August to see the Adonis Blue, Chalkhill Blue and Silver-spotted Skipper (above).
Collard Hill, Street, Somerset Flowery hillside and home to the Large Blue.