It's that time of year again when kids dress up as ghosts and ghouls, some girls dress up in next to nothing and the rest of us, who've left it a little late, poke three holes through a white sheet and pretend we're ghosts. That's right, it's Halloween, nowadays seen by many as just an excuse for children to get sweets and adults to get drunk. But the history of Halloween is much more authentic and bone-chilling than today's festivities might suggest, harking back to the yearly rites of the dark Celtic festival of Samhain.

The Celts had two main festivals: Beltane, which took place at the beginning of May to mark the start of summer, and Samhain, which took place six months later at the end of October, marking the beginning of the long, dark nights of winter (Samhain literally means 'summer's end'). Since the Celts were pastoral people, Samhain marked both an ending and a beginning in the natural, seasonal way of life. The Celts believed that at the time of Samhain the ghosts of the dead walked amongst the living and the souls of those who had died during the year travelled into the afterlife. They lit bonfires and lamps to aid the dead on their journeys and, most importantly, to keep them away from the living. This tradition still exists in Scotland today with widespread festivities on 31 October. The Samhain variation on the scary-faced pumpkin is the 'tumshie lantern' made from a hollowed turnip.

Samhain became the Halloween we are more familiar with around the beginning of the seventh century when missionaries attempted to Christianise the rituals of the Celtic people. In 601 AD Pope Gregory the First issued an edict to his missionaries urging them to adapt the rituals of the old pagan festivals into new, Christian celebrations that would cut out the pagan gods. So Samhain was changed to Hallowmas, or All Saints' Day, to commemorate the souls of the blessed dead who had been canonised that year, and the night before became popularly known as Halloween, All Hallows Eve, or Hollantide.

Halloween is presently something of a mixture between the sacred and sombre rites of Samhain, and a modern cash cow that keeps the plastic spider business afloat. Interestingly, a distinct increase in the number of ghostly sightings and reports of paranormal activity is reported on and around 31 October every year. So perhaps the ghosts of Samhain are not quite safely in afterlife just yet. Best keep a turnip handy, just in case.

Spooked out in Scotland 2008

City of the Dead Hallow'een Festival in Edinburgh

History and horror mix on a special Halloween graveyard tour investigating the world's best documented supernatural case - the Mackenzie poltergeist.
Oct 31, departs 8.30pm, Parliament Square, High Street, Edinburgh. 0131 225 9044, www.blackhart.uk.com, £8.50 (£6.50).

Annual Celtic Samhain Festival at the Scottish Crannog Centre, Loch Tay

Dress up and celebrate at this ancient Celtic festival. Bring a lantern to keep evil at bay and join the torch-lit procession through loch-side woods. There's a carved lantern competition, storytelling, music, apple-ducking, hot soup and fire shows. Booking essential.
Oct 31, 6pm, Scottish Crannog Centre, Kenmore, Loch Tay, 01887 830 583, www.crannog.co.uk, £6, child £3.50.

Frankenstein Pubs Halloween Parties in Edinburgh, Glasgow and Aberdeen

Nine days worth of parties from Friday 24 October to Saturday November. There are monstrous drinks deals throughout the nine days while on the night of Halloween itself there will be gore galore with prizes and giveaways for the best dressed customers.
Frankenstein Pubs, www.frankenstein-pub.co.uk, open daily 10am-1am, free.

Ghosts of Traquair's Past at Traquair House, Peeblesshire

Scotland's oldest inhabited house certainly has a few stories to tell. A hunting lodge for royalty, a sanctuary for Catholic priests, and much more besides, the ghosts of Traquair are coming out this Halloween to give you a guided tour of their old home, with plenty of spooky stories thrown into the mix.
Fri 24 Oct-Sun 26 Oct, departs 7pm & 9pm, Traquair House, Innerleithen, Peeblesshire, 01896 830 323, www.traquair.co.uk, £10, child £8.

Steam and Scream Halloween Weekend at Bo'ness & Kinneil Railway

Get your witch's robes on and go off the rails at the Steam and Scream extravaganza. Trains leave hourly and include a tour of Birkhill Mine with chills, thrills and entertainment plenty.
25 & 26 Oct, departs hourly between 11am-3pm, Bo-ness & Kinneil Railway, Bo'Ness, West Lothian, 01506 822 298, www.srps.org.uk, £7.