Meet the man who runs the world's smallest working 'lighthouse' - which can shine for three miles and is powered by vegetable oil.

Garry Irvine looks after the historic 23ft Harbour Light Tower - climbing its 24 steps three times a week.

The famous tower replaced an original lighthouse which was constructed across the street in 1811.

It provided much-needed light to the well-travelled River Forth in Scotland – but due to its positioning the original light struggled to illuminate the entire crossing.

Students then began to work with civil engineer Robert Stevenson with the aim of finding a suitable solution.

Stevenson and his team painstakingly constructed the Harbour Light Tower in 1817.

It had a new light room which had a better position to illuminate the river – and the Argand lamp from the lighthouse was moved to the new tower.

But as railways began to spread across the country the Queensferry Passage became less and less popular.

The light tower’s flame finally extinguished in 1890 - after the creation of the Forth Rail Bridge.

That was until 2014, when the North Queensferry Heritage Trust were given approval to restore the lamp to full working order.

Today, the light tower is both fully functional and a popular tourist spot and museum.

It is maintained by retiree and Heritage Trust secretary Garry, who moved to North Queensferry around 40 years ago.

Garry has been maintaining the light since retiring ten years ago.

He said: "The little light was built in 1811 in the adjoining lighthouse just across the street but it wasn’t doing the job it was needed to do."

"With the Queensferry Passage being the most important ferry in Scotland at the time, it meant that the actual ferry passage had to be lit."

"They moved the light from the lighthouse over to the little light tower, and that is what we renovated to make it work again."

"We built it from an original based in the National Museum of Edinburgh – so we can truly say it’s the only working light tower in the world."

Garry went on to explain how the Argand lamp is able to provide up to three miles worth of light – by using a reflector which magnifies the flame inside 2000 times.

"The lamp is driven by oil – originally, it was whale oil, but we don’t use that anymore, so it’s vegetable oil now," he said."

"Lighting the lamp is pretty unique and it requires a bit of manipulation of the lamp."

"The lamp is called an Argand lamp, and it was used for most of Robert Stevenson’s lighthouses at the time he was living. "

"The lightkeepers at the time would climb those 24 steps twice a day – sometimes more when they saw the light was out."

"The light can last for about 18 hours with its tank of oil – which is more than sufficient for a cold winters’ day or night."

Garry, who is also an amateur photographer, visits the light room two to three days per week, and has welcomed visitors from over 90 countries to the site.

Named after Queen Margaret, who would regularly make the journey through Queensferry, the passage, the location saw around 300 travellers per day – and the light tower now serves as a museum to one of Scotland’s most important crossings.

"It was the shortest crossing from Fife to Edinburgh, and it was quite popular – it started the communication and transportation age in Scotland," said Garry."

"If anyone is interested in Stevenson lighthouses, this is a great one to tick off your list."

"We can light it by request, and we have signs that give you a little bit of the history."

"You can enjoy what many light keepers did, twice a day over hundreds of years – it’s a very enjoyable experience."