Roseland House, Great Yeldham, Essex. About 5 acres including a paddock of about 3 acres of uncut grass, with a boggy corner and a small spinney to the south. There is also a useful pond for the dragonflies and a garden.

Brookes Reserve, Stisted, Essex. 60 acres managed by the Essex Wildlife Trust.

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

Gosfield public access land, Gosfield, Essex. A small area of set aside land.

Hitchcocks Meadows, Danbury, Essex. Permanent pasture owned by the Essex Wildlife Trust.
Free public access at all times. Nearest parking is the free car park in Mayes Lane.

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.

Canvey Island, Essex. Including West Canvey Marsh, Canvey Wick and Holehaven Creek sea wall.

Bison Hill, Beds. Southern end of the Dunstable Downs. Free public access at any time, free NT car park.
A good site for Duke of Burgundys.

Totternhoe Knolls and Quarry, Beds. A chalk hill and disused chalk quarry preserved for wildlife. Free public access at any time, free NT car park. A good site for Small Blues.

Beacon Hill, Ivinghoe, Bucks. Free public access at any time, free NT car park.
A chalky outcrop of the Chiltern Hills. Known for Duke of Burgundys with many Cowslips.

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.

Gamlingay Wood, Cambs.
An ancient wood on heavy chalky boulder clay, can be very wet underfoot after heavy rain. Free public access at all times with free parking.
I saw Silver washed Fritillaries here in July 2012.

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

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.

Sugley Wood, Gamlingay, Cambs.
Sugley Wood is being managed to develop from farmed land to natural woodland. Free public access at all times with free parking.
This site has a strong colony of Marbled Whites. Clouded Yellows were reported in July 2012.

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.

Therfield Heath, Royston, Hertfordshire. Common land. Steep well-drained slopes over chalk.
Free public access with a free car park.
This site had strong colonies of Chalkhill Blues and Marbled Whites.

RSPB Strumpshaw Fen, Strumpshaw, Norwich.
An RSPB Reserve. Free entry for RSPB members, otherwise a payment is charged. Free parking.
Part of the Norfolk Broads on the north bank of the River Yare. This site is known for its colony of Swallowtail Butterflies.

Ted Ellis Reserve, Wheatfen, Surlingham, Norwich.
Free public access. Free parking.
Part of the Norfolk Broads on the south bank of the River Yare. This site is known for its colony of Swallowtail Butterflies.

Fermyn Woods, Northamptonshire. Owned by the Forestry Commission.
Free public access. Free informal roadside parking.
This site is famous for its colony of Purple Emperors.

Glapthorn Cow Pastures, Glapthorn, Northamptonshire.
Free public access, with informal free parking along the side of an unpaved road opposite to the access.
An ancient wood on heavy soil. Managed by the Wildlife trust for Bedfordshire, Cambridgeshire and Nothamptonshire.
Large areas of Blackthorn specially managed for the Black Hairstreak.

Salcey Forest, Hartwell, Northamptonshire. Owned by the Forestry Commission.
Free public access. The main car park is open from 8.00 am - 7.00 pm. in the summer months (closing at 5.00 pm in winter).
The main car park is Pay and Display, £1 for an hour, £3.00 for the day.
This site is famous for its colony of Wood Whites.

Twywell Hills and Dales Nature Reserve, Northamptonshire.
Free public access. Free car park. Just off the A14 road.

Aston Rowant NNR, Stokenchurch, Oxfordshire. A National Nature Reserve.
Free public access. A free carpark for each side of the reserve, north and south of the M40.
This site features colonies of Adonis Blues, Chalkhill Blues and Silver Spotted Skippers.

Whitecross Green Wood, Buckinghamshire and Oxfordshire (mostly).
A reserve of the Berkshire, Buckinghamshire and Oxfordshire Wildlife Trust.
Free public access with free car parking. There is no roadside notice. Turn off the road opposite to a small thatched cottage, go through two gates into the car park just inside the the wood.

Otmoor, RSPB Reserve and adjacent Roman road.
Free public access. A small, free car park at the end of Otmoor Lane, Beckley.
Known for its Brown Hairstreaks.

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.

Westleton Heath NNR, Westleton, Suffolk. A National Nature Reserve. Ancient acid sandy heath.
Free public access at all times, free parking. Supports a colony of Silver-studded Blues.

Wolves Wood, Hadleigh, Suffolk. An RSPB woodland reserve.
Free parking. A well marked nature trail with Silver-washed fritllaries and White Admirals.