1. Horniman Museum. View this photo on Instagram instagram.com The Horniman Museum is (IMHO) one of London's best museums, but just out the way enough to stay off the radar. Originally this quirky building used to be owned by a wealthy merchant who filled it with things he took a liking to – a stuffed walrus, a papier mâché construction of the goddess Kali, a stuffed Dodo. You know, the usual. As well as the fantastically unusual collection, the grounds also have a conservatory that competes with Kew Gardens, and sweeping views across London. Where: Forest Hill. 2. Peckham Levels. Bex Walton / Via Flickr: bexwalton Opened in 2017 in a giant car park in Peckham, this community project involves a street food market, studio space, bar and live music venues spread out across the seven floors. The majority of the fun bits (food! Drink! Merry making!) are on floors five and six.Where: Peckham. 3. Neal's Yard. View this photo on Instagram instagram.com This hidden corner of Covent Garden is one of the most colourful in the city. Inside is a hodge-podge of restaurants, cafes and shops (all committed to sustainable and ethical commercial practices) that are well worth finding. Where: Covent Garden. 4. Crossness Pumping Station. Andrea Vail / Via Flickr: avail Opened in 1865, this former sewage pumping station may have slightly less than illustrious origins, but is seriously pretty. The Grade 1 Listed building's Victorian cast ironwork is some of the best in the world and can be viewed on selected open days. Where: Thamesmead. 5. The Barbican Conservatory. View this photo on Instagram instagram.com The Barbican Estate may not look like much, but inside is a hidden paradise. The building's leafy conservatory (the second biggest in London!) is not only free to visit, but as of last year stays open late on Saturdays with a pop-up bar.Where: Barbican. 6. The Four Seasons Chinese Restaurant. View this photo on Instagram instagram.com Chinatown is a major draw to London visitors, but locals know that the Four Seasons is the real place to be. Known for its tasty barbecued meats, you can either brave the queues in the three Chinatown branches, or go further afield to find fewer crowds in the original Bayswater branch. Where: Bayswater and Chinatown. 7. Postman’s Park. View this photo on Instagram instagram.com Just a short walk from St Paul's is Postman's Park, a less obvious but no less compelling London sight. Inside this compact public park is the Watts Memorial to Heroic Self-Sacrifice by George Frederick Watts – built in 1900, its plaques tell the stories of those who lost their lives trying to save others.Where: Barbican. 8. The Greenwich Foot Tunnel. It's No Game / Via Flickr: duncanh1 Built in 1902, this 1,215-foot tunnel runs from the Cutty Sark in Greenwich, under the Thames to the Isle of Dogs. The walls are covered in 200,000 white tiles, making for a surreal walk. Where: Greenwich. 9. Little Venice. Holgi / Via Flickr: holgi Though not quite a dead ringer for the Italian Venice, this area of Paddington has Regent's Canal running through it and a number of great pubs and restaurants are centred around its charms. Dreamy boat trips can also be taken down the waters.Where: Paddington. 10. St-Dunstan-in-the-East. View this photo on Instagram instagram.com This church dates back to 1100 but lies in ruin after being hit with a bomb in 1941. Now hauntingly overrun with greenery, this public park is made all the more surreal by its position in the middle of the City of London.Where: Blackfriars. 11. The Natural Philosopher. The Natural Philosopher This secret bar on Hackney road is hidden in the old storeroom of a Mac repair shop. While many of London's other 'speakeasy' style bars are now pretty well-known, this tiny, boozy spot is still discreetly local. Recently taken over by bartender, Josh Powell, the newly revamped cocktail menu features foraged ingredients from the surrounding area.Where: Hackney. 12. Sir John Soane’s Museum. View this photo on Instagram instagram.com Though Sir John Soane was potentially Britain's most famous neoclassical architect, his former home-turned-museum is much less well known. The architect managed to convince the government to preserve his house and collections of work exactly as they were, and nothing has been touched since 1837.Where: Holborn. 13. The House of Dreams. View this photo on Instagram instagram.com Eclectic art fans will find a real treasure at The House of Dreams, the terraced home of textile designer Stephen Wright. He's spent the last twenty or so years transforming it into a chaotically wonderful space, and opens it up a few days each year to visitors.Where: East Dulwich. 14. The Fan Museum. The Fan Museum / Via Facebook: TheFanMuseum The world's first museum solely focused on the preservation and display of fans, this beautiful world heritage site is also home to London's cheapest afternoon tea. At £9 a head for cakes, tea and scones, it's an absolute bargain.Where: Greenwich. 15. Leadenhall Market. View this photo on Instagram instagram.com This covered market is a fantastical sight that dates back to the 14th century. Though meat and fish used to be the order of the day, its modern incarnation is now full of cool boutiques, buzzy wine bars, and delicious restaurants.Where: City of London. 16. Hampstead Bathing Ponds. Marc Barrot / Via Flickr: marcbarrot These swimming ponds are refreshingly chilly and an extremely natural way to take to the water in London – as lovely as the local Lidos are. A single day ticket costs £2, so it's a pretty reasonably priced dip too. Where: Hampstead Heath. 17. The Castle Cinema. The Castle Cinema Since opening in 1913, this space has been a cinema, a shoe factory, a bingo hall and a snooker club. After closing, £57,000 was raised by crowdfunding to restore and reopen the space, which alongside its ornate cinema has an art deco bar. Where: Homerton. 18. Wilton’s Music Hall. Paul Marc Mitchell / Via Wilton's Music Hall This gorgeous space was opened in 1859 as a 'Magnificent New Music Hall'. Magnificent it is, and it now hosts a diverse range of theatre, opera, cabaret and puppetry alongside its musical offerings. One of the few music halls still surviving, the theatre in particular is an untouched masterpiece. Where: Whitechapel.