I'm so unbelievably bored at work, it's painful. I've decided I want to be a grown-up, and go on holiday somewhere for a few days on my own.

It needs to be
a city with nice places to walk around.
somewhere where I won't get murderized or my own.
abroad (I like visiting places in Britain with other people, and I want to see if I can go on a plane on my own and not get lost.
cheap.

suggestions please?