Although the actual links work, the way you've entered them doesn't :-)

Clever old Hols as made so that all you need to do is enter the URL. No need for the "a href=" malarcky!

just simply type in http://www.headheritage.co.uk and always leave a space after the URL ... no putting it in quotes or anything.

I know what you're saying about Stonehenge by the way! It's how I feel about Newgrange. At least they haven't poorly reconstructed Stonehenge .... yet!