<strong>Summer solstice:</strong> Up to 10,000 people are expected at overnight celebrations at England's Stonehenge monument to welcome the summer solstice.
Summer solstice: Up to 10,000 people are expected at overnight celebrations at England's Stonehenge monument to welcome the summer solstice.
Rory Farrell (@roaryfarrell)
<strong>Revelers:</strong> "Mad Al" is one of the mix of pagans, druids and countercultural revelers who have turned up to the event in previous years.
Revelers: "Mad Al" is one of the mix of pagans, druids and countercultural revelers who have turned up to the event in previous years.
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<strong>Neolithic:</strong> Stonehenge is a Neolithic World Heritage site, built an estimated 4,500 years ago.
Neolithic: Stonehenge is a Neolithic World Heritage site, built an estimated 4,500 years ago.
courtesy English Heritage
<strong>Prehistoric engineering: </strong>In a marvel of prehistoric engineering, the stones are aligned with the position of the sun at summer solstice and winter solstice.
Prehistoric engineering: In a marvel of prehistoric engineering, the stones are aligned with the position of the sun at summer solstice and winter solstice.
Stringer/Matt Cardy/Getty Images
<strong>Waiting for dawn:</strong> At 4.52 a.m. on June 21, the sun will rise over the Heel Stone and shine directly into the center of the Stone Circle.
Waiting for dawn: At 4.52 a.m. on June 21, the sun will rise over the Heel Stone and shine directly into the center of the Stone Circle.
Matt Cardy/Getty Images
<strong>Respect for the stones: </strong>No alcohol or amplified music is allowed on site, and celebrants must not climb or stand on the stones.
Respect for the stones: No alcohol or amplified music is allowed on site, and celebrants must not climb or stand on the stones.
<strong>Stones: </strong>The very large standing stones at Stonehenge are made from "sarsen," a local sandstone, but the smaller ones, known as "bluestones," came all the way from Wales.
Stones: The very large standing stones at Stonehenge are made from "sarsen," a local sandstone, but the smaller ones, known as "bluestones," came all the way from Wales.
Adam Stanford © Aerial-Cam Ltd.
<strong>Spring equinox:</strong> The summer celebrations are the most famous, but people -- such as this gathering of druids in 2009 -- also gather for the spring equinox in March.
Spring equinox: The summer celebrations are the most famous, but people -- such as this gathering of druids in 2009 -- also gather for the spring equinox in March.
Matt Cardy/Getty Images
<strong>Autumn equinox: </strong>And then there's the autumn equinox in September.
Autumn equinox: And then there's the autumn equinox in September.
Matt Cardy/Getty Images
<strong>Winter solstice: </strong>Stonehenge's astronomical alignment also occurs on the winter solstice, which falls this year on December 22.
Winter solstice: Stonehenge's astronomical alignment also occurs on the winter solstice, which falls this year on December 22.
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<strong>The nation's monument:</strong> In 2018, Stonehenge celebrated 100 years of public ownership.
The nation's monument: In 2018, Stonehenge celebrated 100 years of public ownership.
Courtesy English Heritage
<strong>Traffic:</strong> The busy A303 is the road that brings most travelers to Stonehenge. This year celebrants are being encouraged to use public transport to reach the site.
Traffic: The busy A303 is the road that brings most travelers to Stonehenge. This year celebrants are being encouraged to use public transport to reach the site.
Matt Cardy/Getty Images