Roseland House, Great Yeldham, Essex. A paddock of about 3 acres of uncut grass, with a boggy corner.
It is sheltered by a spinney to the south and hedges on the east and north sides. There is also a useful pond for the dragonflies.

Danbury Common, Danbury, Essex. A large area of heath owned by the National Trust.

Marks Hall, Coggeshall, Essex. Owned by Marks Hall Estate, a registered charity. One of its woods is known as Thrift Wood (not to be confused with Thrift Wood, Bicknacre).
Free public access to public footpaths through the estate otherwise a charge is made for the Gardens and Arboretum and the woodland walks. See www.markshall.org.uk for opening hours. Note: it is closed on non-Bank-holiday Mondays.
The estate is host to colonies of re-introduced Silver-washed Fritillaries and Purple Emperors.

Stour Wood, Wrabness, Essex. Owned by the Woodland Trust and Leased to the RSPB.
Free public access, with a car park which is open from dawn to 7.00 pm (or dusk if earlier).
This site is famous for its colony of White Admirals.

Thrift Wood, Bicknacre, Essex. Thrift Wood is a 48 acre woodland owned by the Essex Wildlife Trust. It is accessible to the public at all times. Not to be confused with the Thrift Wood at Marks Hall. Link to Thrift Wood at EWT website. This site is famous for its colony of re-introduced Heath Fritillaries.

Brampton Wood, Brampton, Cambridgeshire.
For Black and Purple Hairstreaks, White Admirals and Silver-washed Fritillaries.

Devil's Dyke, Cambridgeshire. An ancient defensive barrier across the chalk over Newmarket Heath to the edge of the Fens.
It is a public footpath with access at all times from each end and from a carpark near Swaffham Bulbeck.
Large numbers of Brimstones can be seen in spring as well as Green Hairstreaks and Orange Tips, and later, Chalkhill Blues.

Fleam Dyke, Cambs. An ancient defensive barrier across the chalk from Balsham to the edge of the Fens at Fulbourne.
It is a public footpath with access at all times from each end and from a lay-by on the A11. Guide
Fleam Dyke is known for its Brimstones, Green hairstreaks, Dark Green Fritillaries and Chalkhill Blues.

Magog Down, Stapleford, Cambridgeshire.
A preserved chalk meadow with Marbled Whites.

Monk's Wood, Cambridgeshire.
I have seen Black Hairstreaks, and Speckled Woods here.

Ouse Washes, Cambridgeshire. Including Engine Bank.
An area of water meadow used for grazing in summer and water overflow and storage in winter. It branches away from the Great Ouse at Earith and runs north-east past Mepal and Manea to rejoin the Great Ouse near Downham Market.
Still supporting a few Wall Butterflies.

Woodwalton Marsh, Woodwalton, Cambs. A Nature reserve of the Bedfordshire, Cambridge, Northamptonshire and Peterborough Wildlife Trust. It is accessible to the public at all times. Link to BCNP website. It is only 1.8 acres but full of interest.
I have seen Grizzled Skippers and Marbled Whites here.

Hadleigh Railway Walk, Hadleigh, Suffolk. A short length of disused railway track bed.
White Admirals appear here from the neighbouring woodland.

North Warren, Aldeburgh, Suffolk. RSPB reserve and length of disused railway track bed.
For Graylings, Small Coppers ansd Small Heaths.