Building an outdoor bike storage solution

Can I just add my 2p, As Tommy rightly says, I have one of those fancy schmancy aluminium ones.

The Bikestore fits three bikes pretty easily, four at a push.

The wooden floor is probably worth it, if only to keep things away from damp concrete underneath. However it really doesn't offer much protection against atmospheric damp. As I'm into obsolete steel bikes that are 30-60 years old, this is a problem.

I only feel 'safe' using this as my garden is totally enclosed by gardens and buildings around it (i.e. there are no alleys or gaps in the terraces where intruders could easily climb in and across many gardens to mine).

Then again I don't use any locking mech on it, which are avaialable when you buy it, one or two 'hasps' with a fairly standard padlock - not exactly a fearsome deterrent. The hasp, I think - as I never fitted the one I got with it, works by securing the arms that allow you to lift the lid (they're attatched to springs inside). These arms are very lightweight aluminium, reckon I could get through those with a shite pocket hacksaw in about a minute. About ten seconds with a decent one.

All in all, not a decent secure place if you're feeling exposed to intruders, I wouldn't say.

I'm about to move house, and I will be taking it with me, as a temporary 'solution' (eeuch I hate that word). I am intending on building a proper lean to in the ginnel down the side of my new place. Which will essentially be a semi-permanent structure, and I'm intending on heating it in some way to keep damp down. And having proper locks on it! And blade wire! And a Somali pirate with an Uzi living in there.

This is, after all, London, my friend.

EDIT PS I really like the ground anchor idea.
But even better is to exhaust all the interior possibilities, as Oliver suggests.