Climb to the top of an ancient monument with striking views.
If you're the type of person who thinks "I'm a Londoner. I will never be able to afford a garden. Why would I want to go to the Garden Museum?", then here's a good reason.
The Lambeth attraction also includes a medieval church tower which, once conquered, offers magnificent views of the Thames and Houses of Parliament.
Access is just £4. Hand over your coins, and up you go. It's not the easiest climb, mind. The spiral stone staircase feels steeper and narrower than comparable buildings, and passing those coming in the other direction is ever-so-teensy-bit-challenging. But you'll be up soon enough.
The views can speak for themselves. Pretty breathtaking. As well as the hub of Westminster, you can look down on the mostly-Tudor Lambeth Palace (London home of the Archbishop of Canterbury), look west towards the unhinged muddle of skyscrapers at Nine Elms, or southward over the less-landmarky streets of Lambeth proper.
The tower has stood here, largely unaltered, since 1377, making it roughly the same age as the Jewel Tower next to Westminster Abbey... albeit with better views. It's part of the church of St Mary, whose nave now houses the Garden Museum.
I don't feel equipped to properly review the Garden Museum. I haven't lived anywhere with a flower bed or lawn since the last century. Many of the exhibits went over my head (especially those on the mezzanine, appropriately). But I got the feeling that those with greener fingers than me would be entranced.
It's certainly a stupendous space to explore. And there are occasional features of interest for the horticulturally ignorant. A Tony Blair garden gnome, for example, or a metal token from the old Vauxhall Pleasure Gardens designed by William Hogarth.
Oh, and there's the historic Pedlar's Acre stained glass window, and the peculiar tomb of the Tradescants. Otherwise, though, the tower will be the big draw here for many garden-less Londoners. It's just £4, whereas the museum + tower is £15 full adult price.
St Mary's tower and Garden Museum can be found at the southern end of Lambeth Bridge. Nearest station Lambeth North/Vauxhall.