Every September, historic buildings and sites that aren't usually accessible to the public open their doors for free one-off tours. Local history groups also run themed walks and talks to coincide with the Heritage Open Days Festival.
Restrictions on indoor gatherings and social distancing mean that most of the buildings which usually take part are not doing so this year - yet others have taken the opportunity to offer virtual behind-the-scenes tours, some in places which would normally be too dangerous for the public to enter, such as Leeds' surviving World War Two air raid shelters.
Anyone registering for a free Heritage Open Days online event wil receive a Zoom link to a tour or presentation by an expert.
Here are some of the most interesting.
Visit the oldest shop in Dewsbury
One of the few face-to-face tours running this year. Greenwoods in Dewsbury is trading as normal, so visitors who book in advance are allowed to pop in during opening hours to look around the clothing and jewellery shop's on-site museum.
Greenwoods has been open since 1860, and the business is home to a collection of historic artifacts and memorabilia from down the ages.
The shop itself - founded by John Greenwood - also contains the original Victorian cabinets and other fittings. The archives include photographs of past employees.
Museum visiting hours are 10am-3pm on September 12 and 16. Pre-book by calling 01924 461198 or emailing [email protected]
See the paupers' graveyard at a Victorian lunatic asylum
High Royds in Menston was once a forbidding lunatic asylum where people were incarcerated for years before a more sympathetic era of mental health treatment dawned. The main buildings have since been converted into housing, but the old graveyard - where patients were buried in unmarked plots - has been preserved and restored as a memorial garden.
Almost 3,000 people are interred there, and the chapel contains information about their lives. A remembrance service will be held on Sunday September 20 at 4.30pm to commemorate them, and visitors will have the chance to look around the area.
You don't need to book and access is next to the ambulance station on Buckle Lane.
A talk about Leeds' lost zoo
The Leeds Zoological and Botanical Gardens were a Victorian project to bring exotic species and recreational opportunities for the working classes to the growing suburb of Headingley. Yet the venture failed spectacularly, and the land was later sold for housebuilding. Only the bear pit on Cardigan Road remains.
This illustrated virtual talk by Leeds Central Library, via Zoom, will cover the history of the attraction and its later incarnation, the Royal Park.
The presentation will be given by Eveleigh Bradford on Friday September 18 from 1-2pm. Visit https://www.ticketsource.co.uk/leedslibraryevents before 11am on the day to sign up - you'll then by sent a Zoom link.
A virtual tour of a World War Two air raid shelter in Leeds
Thirty-one public air raid shelters were built beneath parks in Leeds during World War Two, and many of these survive today, albeit with sealed entrances and little or no access.
This online tour will provide a glimpse inside the Woodhouse Moor shelter, which was bricked up and planted over after the end of the war. There will also be a 3D model showing how the shelter would have looked in 1940. The hosts are Leeds Beckett University historian Dr Henry Irving and 3D heritage artist Jorge de Pedro.
The talk takes place on Saturday September 19 at 2pm. Register at https://www.eventbrite.co.uk/e/inside-the-hidden-shelters-tickets-114652891886 to be sent a Zoom link.
A chance to see inside Fishergate Postern Tower in York
The postern tower is rarely open to the public, but Friends of York Walls volunteers offer guided tours on Heritage Open Days and are doing so again this year, with some social distancing restrictions.
The 16th-century watch tower has a 500-year-old spiral staircase, a Tudor toilet and a timber roof.
Tours are running on September 12 and 19 from 10am-4pm and you don't need to book.
Visit a Georgian watermill
The restored Howsham Mill sits on an island in the River Derwent, near York, It's surrounded by nature and wildlife, and there's a turbine that generates hydroelectricity.
You can visit without booking on Sunday September 13 from 10.30am-5pm.
Explore the last surviving railway plant nursery in Britain
During World War Two, the London and North Eastern Railway hit upon the idea of opening their own plant nurseries, from which they could grow their own produce to supply railway hotels and staff canteens.
Poppleton, near York, is the only one still in existence, and is now run by volunteers as a charity for people recovering from health issues.
After the war, the site was used to grow plants for railway station displays, events and landscaping schemes.
As well as the greenhouses, there are narrow gauge and model railways to enjoy, as well as a cacti collection and Dig for Victory displays.
Drop in from 10am-4pm on Saturday September 12.
The youth hostel in Beverley that used to be a medieval friary
The Friary Youth Hostel was built on the site of an old Dominican friary beside Beverley Minster that few people know exists.
The present buildings are thought to have been the library and dormitory, although the church and cloisters were lost beneath the railway line and a road.
There is a great hall with a 15th-century roof, wall paintings that can only be viewed on Heritage Open Days and a restored limestone fireplace. Discover how the friars met their fate and how the building was pillaged during the Civil War.
Visit between 11am-4pm on Saturday September 12.
See the secret gardens of Beverley Minster for the first time
The secret garden of Beverley Minster has never been seen by the general public before, although the Quiet Garden is open to visitors.
Described as a wildlife haven, the Minster now has plans to develop this tranquil space so that it can be used more often.
There are also plans for a new wildflower meadow in the churchyard.
Visit on September 11, 12 or 13 from 11am-4pm (1pm on Sunday).
A 17th-century house in Bridlington Old Town
The gardens of Bestworth House on High Street are only open to the public on rare occasions - the property is privately owned.
When the house was built in the 17th century, the Old Town was home to doctors, apothecaries, attorneys and merchants. From the rear of Bestworth House, you can also admire the surrounding Georgian buildings.
Drop in from 11am-5pm on September 12 and 13.
Go on a murder walk in Hull
Local historian David Smith will host two walks at 3pm on September 11 and 18.
The guided tour takes visitors to some of the oldest parts of Hull, where they will learn about gruesome murders to have taken place in the port city - including a spate of child killings and a case which involved Scotland Yard officers.
Meet at the Cenotaph opposite the Royal Hotel on Ferensway.
Advance booking is required - contact Mr Smith on [email protected]
See inside Sheffield's only surviving Victorian bath house
Guided 40-minute tours of Birley Spa, a preserved Victorian bath house, will run on September 11, 12, 13, 18, 19 and 20, starting at 12pm, 1.30pm and 3pm.
The spa has a spring-fed plunge pool and its grounds are home to wildlife including kingfishers.
Book in advance by emailing Fiona Milne at [email protected]
The Sheffield library with a secret history
Broomhill Library is housed inside a Victorian villa in the student suburb. Known originally as Oriel House, it was built in 1870 and was home to prominent Sheffield families before being passed to the library service in 1957.
A virtual tour of all four floors will reveal secrets and fascinating historic features.
Check the Broomhill Library website from September 11 for information on how to access a Zoom tour.
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