Does the womb take up all of a woman's body?

:-)#

I've always thought it was because they wanted them to look big and impressive, but could only really build a chamber the span of the biggest stone (lack of arches).

If you can't make the inside big, make the outside big instead.

It also carries on today - Church spires don't need to be that big, nor do French/Flemish town hall towers.

Hetty Pegler's Tump and West Kennet are both examples of Cotswold-Severn type long barrows. Littlestone is wrong; in fact the two that you mention go farther in than most. Some have just a single chamber. At Avebury, two have been excavated and no chambers whatsoever have been found, which I find illuminating.

Baz

The Irish court tomb, which is almost certainly related in some way to the British long barrows, also have galleries that go back not much past half way down the cairn. There are exceptions, natch, but they are exceptions.

I think Kammer said it best.