What is summer solstice?
Summer solstice is the longest day of the year and beginning of summer, according to astronomers.
The date usually falls between June 20 and 22, every year – but in 2018 it falls on Thursday June 21.
Also known as midsummer, the day defines the moment Earth reaches its maximum rotational axis of 23.5 degrees towards the Sun.
The day has the longest period of daylight in the Northern Hemisphere, while the Southern Hemisphere experiences its shortest day.
Sadly, for the UK and other countries, the days will begin getting shorter again after Thursday June 21.
There will be 16 hours and 38 minutes of daylight on June 21, starting at 4.43am and ending at 9.21pm.
What is midsummer and what rituals and traditions are associated with it?
Midsummer is another common expression for the summer solstice, although the date varies in different cultures.
Pagans introduced the day as a marker between the planting and harvesting seasons.
Celebrations typically involve holding bonfires – to cleanse against evil spirits – and feasting.
In the UK, summer solstice or midsummer celebrations focus around Stonehenge.
Thousands of revellers attend the World Heritage site to watch the one day of the year when the sunrises above the Heel Stone.
Stonehenge is believed to have been built between 3,000 BC and 2,000 BC and has long been a place of worship and celebration.
Some Christian countries also use midsummer to honour the religious figure John The Baptist, who baptised Jesus.
Bulgaria mixes both holidays with a fire ritual called Nestinarstvo, in which worshippers dance barefoot on smouldering embers.
Lighting bonfires is still a common occurrence in many European countries – maypole dancing and festivals are also popular.
Does Stonehenge have a festival?
Yes, it does. The Stonehenge Solstice Festival, now in its 10th year, runs from June 18 to 21.
The four-day hippie festival includes live music and spiritual workshops.
Organisers say they are the nearest site to Stonehenge, located only 2.2 miles by road or 4.5 miles walking distance.