Doors Open Day began in 1990, with 44 events in and Ayr. But in the past 34 years it has expanded to cover the whole of Scotland. Each September, hundreds of buildings, historic sites, and unique spaces across Scotland open their doors to the public for free - from stately homes to working factories, modern eco-buildings and places of worship, the variety of venues is vast.
Doors Open Day is billed as Scotland’s largest free festival that celebrates architecture, culture, and heritage. Visitors are invited to uncover hidden gems and experience familiar places through fresh eyes.
The Doors Open Days events take place on different days in different parts of the country – Midlothian and West Lothian have theirs this weekend, September 14-15; Edinburgh and East Lothian go two weeks later, on September 28-29.
Last year, more than 159,000 visits were recorded as part of Doors Open Day. And the Scottish Civic Trust, which co-ordinates the scheme nationally, says there are lots of new venues taking part this year.
Take a look here at some of what will be happening in Midlothian and West Lothian.

1. Arniston House
Steeped in more than 450 years of history, Arniston has been home to the Dundas family since 1571. Arniston House is a magnificent William Adam Palladian style Manor Home commissioned in 1724. It features stunning architecture, stucco works, a beautiful collection of art, furnishing and portraits by renown artists such as Raeburn, Ramsay and Alexander Nasmyth. Open: Saturday 14 September, 10am-4pm. Guided tours on the hour. | Scottish Civic Trust

2. Cockpen and Carrington Parish Church
A 200 year old, A-listed building, the Church sits in Cockpen cemetery, surrounded by beautiful trees. The bell in the Church tower is Flemish in origin and regarded as somewhat unique. It is rung every Sunday prior to worship, as welll as on special occasions. The Church also has a magnificent Wadsworth Pipe Organ. Open: Saturday 14 September, 12-4pm. | TSPL Photo: Justin Spittle

3. Cousland Smiddy and Heritage Hub
There's an early 18th century blacksmith's workshop, Victorian cottage, other buildings and organic allotments in the former gardens. It is believed there has been a working smiddy on this site since at least 1703. The resident farrier will be working at the forge throughout the day, demonstrating the art of horseshoe making. Open: Saturday 14 September, 10am-4pm. | Scottish Civic Trust

4. Crichton Collegiate Church
Built as a Collegiate Church by Sir William Crichton, Lord Chancellor of Scotland in the time of King James II, this building boasts a fine suite of stained glass windows by Ballantine and Gardiner. The pipe organ dates from 1898 and was built by Joseph Brook. The site has been used for Christian worship for nearly 600 years. Open: Saturday 14 September, 10am-4pm. There will be a demonstration of the pipe organ, 2.30-3.30pm. | Google