The 40th anniversary of Londonderry’s Halloween festival has come to a spectacular close, with a carnival parade and fireworks display lighting up the skies over the River Foyle.

From its humble beginnings in the 1980s, the festival has grown to become what organisers have called Europe’s largest Halloween celebration.

This year, Derry marked four decades of the festival with events inspired by folklore, mythology and the traditions of Samhain, the ancient Celtic festival from which Halloween has its roots.

Now a major fixture in the city’s calendar, the final day of the festival attracted visitors from around the world, who joined in the celebrations with all of the ghosts, ghouls and goblins.

Saturday’s programme featured events across the city and district, culminating in the traditional carnival parade with costumes, floats, music and dance performances.

Thousands of revellers then lined up along the riverfront to watch the dazzling fireworks display to mark the close of the festival’s 40th year.

Strabane also hosted trick-or-treat trails, live performances and interactive activities before a fireworks display at the Melvin Sports Complex.

A number of spooky events also took place in neighbouring Artigarvan, Castlederg, and Newtownstewart.

The festival is now promoted across the UK, North America, Europe and Australia, while international broadcasters and media organisations regularly feature Derry Halloween.

In 2015, a USA Today readers’ poll named Derry the world’s best Halloween destination, while the New York Times later included it in a list of leading spooky-season travel destinations.

About a quarter of the 120,000 people estimated to have attended the festival over the past four days are thought to have travelled from outside Northern Ireland.

Tourism Northern Ireland chief executive Laura McCorry praised the importance of Derry Halloween in attracting visitors to the north west and boosting its economy.

“Tourism is really important for Northern Ireland,” she said.

“It supports over 70,000 jobs and currently contributes £1.2bn in revenue to the economy.

“We have ambitions to double [that figure] so events like this provide a much-needed boost for the local economy,” McCorry said.

“They give visitors a reason to come here and spend longer in our cities – that’s really crucial for Northern Ireland as a whole.”

Derry City and Strabane District Council spent about £800,000 on this year’s Halloween festival.

Festival and events manager Jacqueline Whoriskey said the last estimate of the economic return was about £7.4m.

“For every pound spent there is a significant return and that’s great for the whole area,” she said.

Izzy and Duana arrived in Northern Ireland on Saturday morning from Seattle in the US.

Duana first heard about Derry Halloween last year after seeing a video of the parade on social media.

“We just had to make the trip over and we are loving it,” she said.

Closer to home, the Toye family from Derry brought a little Scooby-Doo magic to the celebrations.

Dressed as the Mystery Inc gang, they said they enjoyed a frightfully good night in the city.

The family dress up every year and love going to the carnival.

Their plans tonight included grabbing hot chocolate, a spot of trick-or-treating and watching the fireworks.

Aoife Thomas, the sales manager at Holiday Inn Express in Derry, said guests from around the world stayed at their hotel throughout the week.

She said the hotel staff dress up in colourful costumes every year and have great craic with the international visitors.

Businesses in the city also heard the sound of tills ringing out over screams of terror this Halloween, as many workers got into the spooky spirit during one of their busiest weeks of the year.

Caroline Casey, the store manager at O’Neill’s Sportswear, said their shop was transformed into a spooky graveyard, complete with three skeletons – including a mischievous one that interacted with the crowds.

The performance in the upstairs window of the store was created especially for this year’s festival, which has the theme “It’s in our Bones”.

Bar manager Paul Ansell loved seeing all the fantastic costumes throughout the Halloween festival and said his bar had done a roaring trade across the four days, serving drinks to crowds of revellers.

“If you aren’t dressed up for Derry Halloween you are the odd one out here,” said Ansell, of Castle and Cove Bar on Magazine Street.

“It is brilliant how the whole festival has developed and grown over the years.”