In reply to Moacs:
> Conversely, what's the *lowest* first bolt? There's a couple at head-level on Portland.
I was going to ask the same question! I suspect one or two of those might be mine...hanging off an ab rope you can lose your sense of perspective - the ground looks a long way away so you think, "ah, I'll put another one in here" - then lower down to touch the ground in a few metres!
There again, they could be belay bolts for those gnarly mudslides (I usually put them in sideways as a sign that, no, I haven't put a protection bolt in 1m above the ground!)