Hundreds of hidden spaces will open their doors to the public as part of the annual festival which allows Londoners to peek behind their closed doors.
The first batch of listings has been released for the nine-day event which takes place from September 12 to 20.
They include tickets for popular tours such as No. 10 Downing Street, BT Tower, Broadcasting House and a 40th anniversary glimpse inside the Richard Rogers-designed Lloyd’s Building in the City of London.
Victorian Leadenhall Market will offer guided tours with rare access to the Roman Basilica and Forum remains beneath the historic site.
And in east London there's a recording studio used by huge music stars and a Victorian paint factory which has a Second World War bunker beneath the beneath it.
This year is the festival’s 35th edition, featuring the biggest ever range of buildings across the capital - many of which are normally closed to the public.
Organised by the charity Open City, the festival features landmark locations, private homes, heritage sites, workplaces, and industrial spaces, all opening for free.
North London sites include houses, schools and museums such as The Freud Museum, Keats House and the modernist Isokon Building in Hampstead - the respective former homes of Sigmund Freud, John Keats and Agatha Christie.
There's The Old Holloway Fire Station which has been taken over by a community group and The Zaha Hadid Foundation archive in Clerkenwell, which offers limited access to the public, and includes drawings, models, and personal items belonging to the late architect.
In Wembley there's Punchdrunk Enrichment Stores, an immersive theatre space which puts on children's shows.
Visitors will have the chance to explore the Barbican Conservatory, with talks on the upcoming Barbican Renewal project and a plant adoption event.
Strongroom recording studio in Shoreditch, which has hosted artists such as Nick Cave, Radiohead, The Prodigy, and The Chemical Brothers, will also open its doors, offering a glimpse into the inner workings of an active award-winning recording studio.
And in east London is the remarkable The Print House, in the former Reeves & Sons paint factory which was built in 1870 and survived the Blitz - complete with a wartime bunker.
Decades later, after housing railway engineers and hosting 1980s reggae sound systems, Bootstrap Charity saved it from developers and it's now part of the Dalston Cultural Quarter with art exhibitions theatre rehearsal studios, affordable office space and the Dalston Roof Park.
Celia Mead, director of the London Open House Festival, said: "We’re delighted that our 35th edition of London Open House is going stronger than ever.
"There is a real need for access to places and spaces of all types - wherever you can’t normally get inside - and the result is shared experience, a sense of belonging and even joy.
"In fact, many visitors tell us that Open House is the highlight of their year and they look forward to finding out what is in the programme as if it were Christmas."
Visitors can preview the programme at openhouse.org.uk, with additional listings to be added throughout the summer.
General bookings will open at 12pm on August 19, though many sites will be open for drop-in visits.
