1. Boilermaker, Nottingham
2. Panda and Sons, Edinburgh
3. The Maven, Leeds
4. The Lost and Found, Birmingham
This "Victorian botanical hideaway" has a secret behind its bookcase. You'll need to ask the staff for a key. If you can't get to Brum, then check out The Lost and Found's YouTube channel, where they walk you through their most popular cocktails.
5. Milk Thistle, Bristol
6. Flat 0/1, Glasgow
7. The Gin Parlour at Jekyll & Hyde, Birmingham
8. Underdog, London
A cocktail bar beneath a Brewdog pub, Underdog's ale cocktails will make beer fans very hoppy (sorry). Fret not, they also do normal cocktails too.
9. Ernest, Newcastle
Ernest is easy to find, once you know what you're looking for. Tucked away under a bridge, by the Biscuit Factory, Ernest is a cosy café and bar, open all hours. "Relaxed during the day and lively at night" aka ideal.
If you're looking for something a little more unique, keep an eye out for Boiler Shop Steamer, a monthly food, drink, music, and art event, held in the Boiler Shop (behind Central Station).
10. Beese's Bar & Tea Gardens, Bristol
Bristol's best-kept secret. And for good reason: You can only reach this riverside haven by boat (or by a hidden private path, if you're very determined). Once you dock, you can indulge in a cream tea, or sit on the deck with a cold glass of wine and watch the river flow by. Beese's is open Easter to September yearly.
11. Ladies and Gentlemen, London
12. Hausbar, Bristol
Tucked beneath an Indian restaurant, Hausbar is a bar that doesn't muck about. A little bit kitsch, but terribly classy, there's a German twist to the decor and the drinks are strong.
13. Neighbourhood, Brighton
Not "hidden", strictly speaking, but this local favourite has one of the best secret beer gardens in the city. The garden is a suntrap in the summer, and has heaters when it gets a bit nippy. Plus, the hot dogs are boss.
14. The Flying Duck, Glasgow
15. Porter's, Cardiff
A hidden gem in Cardiff, this unassuming and tucked-away bar (near the Motorpoint arena) has a fantastic selection of craft beers, and really punches above its weight. If you're keen, they also have a pub theatre attached.
Bonus! They also have a crazy golf course.
16. Bourne & Hollingsworth, London
A compact parlour bar, down some treacherous Soho steps, B&H's drinks are potent and delicious, and often served in their signature teacups. They also have two other locations (Clerkenwell and Goodge St).
Want more London recommendations? Here are 17 Underground Bars In London You Must Visit Before You Die.