Warren

Folkestone Warren is the only place to find grayling butterflies in Kent, so on a suitably hot day I went in pursuit. It's a large area to cover, but the most likely area was covered first, and provided a great number of butterflies...but no graylings.
The parched hillside was Mediterranean in the heat, with perfumes of herbs swirling all around.
There were plenty of walls, and other notables included a couple of pairs of clouded yellows flying fast together. The list for the walk was good, and counting was made easier by a sudden decline in painted lady numbers, but no graylings:

Gatekeeper (lots and lots)
Small White (lots)
Large White (quite a few)
Common Blue (plenty)
Marbled White 12
Wall Brown 11
Painted Lady (only) 8
Small Heath 8
Brown Argus 7
Speckled Wood 6
Clouded Yellow 5
Adonis Blue 5
Small Copper 3
Dingy Skipper 2
Red Admiral 1
Peacock 1
Ringlet 1
A surprise plant was figwort, and I couldn't remember where I'd seen it before, until I searched the blogopedia - it was in a wetland near Faversham, about 6 feet high compared with this lonely specimen of 6" on a chalk hillside.

Taking a breather near a clump of marjoram, a male adonis blue was very confiding, allowing a prolonged photo shoot.
By contrast, dingy skippers were flighty.
Brown argus

Finally, is this a grayling? No, it's another wall, doing a passable imitation of grayling camouflage, but given away by being visible.
The valuable UK Butterfly Monitoring Scheme website confirms comments on the the Kent Butterflies website that this is a vintage year for walls, stemming the steep decline over the past few years.

The list below shows counts of first and second generation walls on a Folkestone Downs transect, from 1995 to 2007, with a peak of 97 and lowest of just one in 2007. Most walks in the area provide up to a dozen at a time, with an astonishing 43 counted at Shakespeare cliff last week.

Generations

Year 1st 2nd

1995 13 25

1996 12 17

1997 2 12

1998 33 64

1999 12 14
2000 n/a

2001 16 25
2002 13 21

2003 8 11

2004 2 12

2005 6 16

2006 8 4

2007 0 1

As a momento mori of the ups and downs of butterfly numbers, Ullyett wrote in the late 1800s of "the Dark Green Fritillary, a few of the Large Tortoiseshell with an occasional Queen of Spain, a Camberwell Beauty, or a Bath White" being seen on the Warren. He also considered theSilver Y moth to be a "great rarity".