Most tourists and many Londoners have made the impatient mistake of tackling Covent Gardens tube's 193 steps instead of waiting their turn at the lifts during rush hour on a sticky summer day. If you think that sounds like a nightmare here's a genuinely daunting thought for Halloween: making the 842-step climb to the top of the BT tower. But then again those who choose to ascend to the 34th floor will be rewarded with a pretty spectacular, usually inaccessible, view of London, rather than the sight of unnerving metallic street performers. Plus it's for a good cause, those taking part will be asked to raise a minimum of £200 for UK charity Action on Hearing Loss. Halloween climbers are encouraged to don face paints and non-trip hazard costumes, although the likelihood is that those that don't choose to make the effort will still emerge resembling sweaty slow moving zombies (see Covent Garden Tube). Londoners love a bit of mashocism for a worthy organisation and are suckers for a good view so tickets are expected to sell fast, if you're keen you can register online here.