How do I delete an old facebook account I no longer have access to?

[Sabri]

You can't delete facebook accounts, but you can deactivate them (pretty much the same as deleting, but you'll have the option to reactivate the account), and while the account is deactivated, no one can see your photos, it will be like you're account isn't even there.
To do that... Go to Account Settings > Security... at the bottom of that page you'll find "Deactivate your account.", click it, enter the password, and your account will be as good as gone.\
If you want to reactivated just log in normally.