The Castle Climbing Centre Pic: Malc McDonald

Clissold House
Clissold Park, Stoke Newington Church Street N16 9HL
Sunday 11am-4pm
This 18th century mansion was originally built for Jonathan Hoare, a Quaker, philanthropist, and anti-slavery campaigner. The house lies in the beloved Clissold Park, with features including large ornate windows, a winding staircase and a domed skylight. After extensive renovations, the building was removed from the 'Heritage at Risk Register'.

Village Underground
54 Holywell Lane EC2A 3PQ
Saturday 9:30am-6:d0pm
The Village Underground is both a creative community and an arts venue located in a warehouse. The space is most notably known for the use of four recycled tube train carriages resting on the roof, which are used as artist's studios. The Village Underground is also known for being run almost entirely on solar panels and energy from wind turbines.

The Castle Climbing Centre
Green Lanes N4 2HA
Saturday and Sunday, 10am-7pm
This Victorian water pumping station looks like an imposing fortress from the outside. On the inside, however, has been converted to an indoor climbing centre, where colorful knobs and bulbs line the walls for bouldering, lead climbing, and top roping. Visitors will gain access to the impressive tower, which is usually closed to the public.

Kingsland Basin Moorings
Kingsland Basin Moorings (via towpath) N1 5BB
Sunday 10am-5pm
Gain access to the communal areas and interiors of several narrowboats along the Regents Canal. Founded in 1983, the Canal Hackney Users Group (or CHUG) manages the moorings, which provide affordable housing options. The group has also created a Floating Allotment, and has worked to educate people on the environmental concerns of the canal.

Round Chapel
Lower Clapton Road E5 0LY
Sunday 11am-4:30pm
The Clapton Park Chapel, now known as the Round Chapel, was one of the most important nonconformist buildings in London. The building is now an arts and community venue after more than 1 million was spent on repairs. Notable architectural features include the use of iron throughout the construction of the building, the flat ceiling, horseshoe shaped floorplan, arched windows and octagonal towers.

Auditorium of Wilton's Music Hall Pic: Wikicommons

Balfron Tower
St Leonard's Road E14 0QT
If Balfron Tower looks familiar, it's probably because it's architect, Erno Goldfinger was also behind the famed Trellick Tower. The Brutalist residential building is famous for its separate lift shaft, connected to the main structure with walkways on every third floor. Goldfinger was so pleased with his work that he promptly moved into the building himself. Visitors will be able to access the entry area, lifts, walkways, as well as one of the flats.

Trinity Buoy Wharf / Container City
64 Orchard Place E14 0JY
Saturday and Sunday 11am-4pm
Trinity Buoy Wharf is home to London's only lighthouse. The first Container City, a complex consisting of shipping containers, was also installed at the site in 2001. The first of its kind, Container City I was seen as a massive success, given its cost efficient and environmentally friendly building methods. Container City I is currently used as both living and working spaces, although the modular shipping containers have been adopted as classrooms, nurseries, retail spaces, and community centers elsewhere.

Coborn House
1a Tredegar Square E3 5AD
Saturday 10am-2pm
This Victorian era warehouse has been renovated to create high end properties while retaining much of the building's distinct features like vaulted roofs and arched brickwork. The result is sleek and modern, while hinting at the building's industrial history. Coborn House was commended in the British Home Awards, hosted by The Sunday Times in 2013.

Wilton's Music Hall
Graces Alley, Ensign Street E1 8JB
Saturday 12pm-11pm
Wilton's Music Hall is the oldest surviving music hall in London. Originally an ale house, it is now being used as a multi-purpose performance venue. Despite the visibly old interior, it maintains an air of grandeur with vaulted ceilings, balconies, and cast iron columns.

Trinity Laban Conservatoire of Music and Dance. Pic: DeptfordJon

The Green Man (Phoenix Community Housing)
355 Bromley Road SE6 2RP
Saturday 11am-3:30pm. Pre-book ONLY on openhouse@black-architecture.com
Named after the former pub, The Green Man is a notable piece of architecture that includes a cafe, credit union, training kitchen, business units and a market square. The building also boasts specially designed heating and cooling systems, automatic lights that turn off when certain spaces are unoccupied, and a green roof.

Spring Gardens
Ennersdale Road SE13 6JQ
Saturday 1pm-4:30pm. *No visitors under the age of 18
Spring Gardens is an intentionally designed hostel for the homeless; unlike the previous Ennersdale House, which featured dark and isolating components, the hostel is bright, spacious, and inviting. With a garden at its centre, and large glass windows that look out into this green space, Spring Gardens "challenges assumptions about what a homeless shelter should look like".

Blackheath Quaker Meeting House
Lawn Terrace, Blackheath SE3 9LL
Saturday 10am-5pm.
Completed in 1972, the Blackheath Quaker Meeting House has won a Civic Trust Award. Built in a concrete Brutalist style, the house is based around the octagonal meeting room with glass windows in a raised skylight structure.

Glass Mill Leisure Centre
41 Loampit Vale SE13 7FT
Saturday and Sunday 1pm-5pm
The Glass Mill Leisure Centre can be found on the first three floors of a high rise apartment building. Marked by a colorful glass tiled exterior, the interior houses a swimming pool, gym, exercise studio, and climbing wall. The leisure centre won the award for Best Built Project- Community Scale Scheme in 2014.

Trinity Laban Conservatoire of Music and Dance
Creekside SE8 3DZ
Saturday tours: 3pm, 4pm only. Sunday tours: 1pm, 2pm only.
Located along the Deptford Creek, the Trinity Laban Conservatoire is the largest purpose-built contemporary dance centre in the world. Designed by the famed architecture firm Herzon & de Meuron, also responsible for the Tate Modern, the building is notable for is translucent facade and use of color and light.

White Horse Manor School Pic: TECU Consulting UK

The Stanley Halls
12 South Norwood Hill SE25 6AB
Saturday 10am-5pm
A complex of unique Edwardian buildings, Stanley Halls is now used as a public space, theatre, and gallery. The building, featuring a prominent clock tower, was built in 1903. It fell into disrepair in the 60s and has recently been revitalised by the Stanley People's Initiative. Get full access to the entire building, including look behind the stage. Tours are also available on a first come first serve basis.

Whitehorse Manor Infant and Junior Schools
Whitehouse Road, Thorton Heath CR7 8SB
Saturday 10am-1pm
The expansion of this school in 2013 led to surprising results, as the Victorian brick structure was transformed with a glaring golden facade to make way for more students. The use of timber slats on the ceilings of each room create a uniformity to the fragmented exterior. Tours are available every half hour on a first come first serve basis.

Croydon Town Hall and Clocktower Complex
Katharine Street CR9 1ET
Saturday 10am-1pm
The Town Hall was constructed in the late 19th century and the Clocktower Complex was added in 1993. The buildings have been completely renovated and now house the Croydon Museum as well as the newly re-opened David Lean Cinema. This grand, red structure has been an essential part of Croydon's landscape; attend a tour of the building every hour, on the hour from 10am - 1pm.

Shirley Windmill
Postmill Close, Upper Shirely Road Croydon CR0 5DY
Sunday 12pm-5pm
The existence of the Shirley Windmill has been continually threatened throughout its long history. The original windmill was destroyed by a fire, and the present brick structure has exchanged hands numerous times. It finally secured its position as a heritage site. The windmill is the only surviving one in Croydon. Regular tours available on a first come first serve basis.