Fair points, Nigel and that is why I am thinking that different sized henges in different parts of the country might have had diferent purposes. Sure - if you look at the big Wessex henges and those up north like Mayburgh - you get an impression of thing on the grand scale. You even get that feeling down south with the henge at Maxey, but when you see the little ones of Essex it does seem different. Smaller, no stones at all, no hills to align to. Can't help thinking stock markets ;o)

"Boxted has entrances at N and S, Corringham at SW and NE, Cressing at E, Felsted at W, Wigborough at SE, Little Baddow at N and S, Little Bromley at NW and SE, Sturmer at NE. The others have no visible gaps.

That suggests to me that these henges do not have a religious/ritual purpose. The entrances are not consistent and are not aligned to sunsets, sunrises or anything else. "

Except for the N & S mentioned they are all sunrise/sunset alignments. Passage tombs vary in the alignment of their passages and include NE, SW, E, W, NW & SE. A few even face N. So, by your own arguement, passage tombs are perhaps covered pig pens and "do not have a religious/ritual purpose." ?

Alignments do not have to be to a significant sunrise either. They could be aligned to the place the sun rose on the day of an important day. Examples of this can be found in some very early churches which are aligned not to the east, but to the sunrise on the local Saint's day.

The above does not mean I would totally disagree that henges could have been simply pig pens or whatever, but I do not accept the argument above as anywhere near valid.