The Solar Pyramid

The Solar Pyramid will be world’s largest solar timepiece and a sculptural structure of unsurpassed scale and beauty.

Richard Swain and Adam Walkden

Created by artist/architects Richard Lester Swain and Adam Walkden as a dynamic exploration of the transience of time, the Solar Pyramid is both a monumental work of art and a unique scientific instrument.

Of a truly topographical scale, the Solar Pyramid will rise out of the landscape as three inclined blades of mirror polished gold and green steel, to form the illusion of pyramidal shape. The point of largest blade, or gnomon, will be 75 metres (246 ft) above a raised oval horizontal plane, 100 metres (328 ft) in length. A ‘planetary piazza’ exploring the complex relationship of motions of the planet Earth and our star the Sun, and accurately recording the passage of time past, present and future.

A timeless experience of Time. A new Stonehenge for a New Age. A golden pyramid of the sun.

Key Features

  • The World’s Largest Solar Timepiece and a sculptural structure of breathtaking scale and beauty.
  • A national landmark, and visitor attraction of international significance.
  • Associated with two world centres of excellence – the Institute of Astronomy, Cambridge and the Royal Observatory Greenwich via Dr Robin Catchpole.
  • An interactive scientific instrument, and huge educational resource, exploring the relationship of the earth and the sun.
  • A credible project management team of international repute.
  • A visionary and iconic symbol for a challenging future. A ‘peoples memorial’, a statement of hope and renewal, of success and ambition.
  • An environmentally sustainable structure harnessing heat and energy from the sun.

A dynamic demonstration of the enmeshing of space-time and form, transience and permanence, on a truly monumental scale.

Richard Swain

The Astronomy of the Solar Pyramid

A visit to the Solar Pyramid will not only help to reconnect us with the rhythms of our natural environment, but stimulate us to consider to what extent the Sun is the ultimate source of the energy that powers our world.

Dr. Robin Catchpole, Institute of Astronomy, Cambridge


Push a stick in the earth and the shadow of the stick cast by the Sun on the ground will move through the day, marking the passage of time. At midday, local solar time, the Sun will be due south and the shadow will lie due north of the stick (in the northern hemisphere). This will not make a good solar clock, because, during the year as we go from summer to winter, the Sun will be at a different height in the sky at the same Solar time and the stick shadow will lie in a slightly different direction.

This problem is overcome in the conventional sundial by aligning the pointer that casts the shadow, parallel to the Earth’s axis of rotation. This means that the pointer is aligned north south and is tilted at an angle identical to the latitude of the sundial site. At night, the pointer points very close to the Pole Star, at the place around which the night sky seems to rotate.

A sundial gives us time by the Sun, but this is no longer the sort of time we use to regulate our lives for the simple reason that “Sun hours” do not have the same length all the year round. This is the reason that a sundial has a table of corrections, referred to as the “Equation of Time”, which must be applied to the “Sun time” to get clock time. It is also the reason for the word “mean” in Greenwich Mean Time (GMT).

Adam, Richard and Dr Catchpole viewing the scale model of the Solar Pyramid at the Space Time Gallery of the Royal Observatory at Greenwich

The Solar Pyramid

The Solar Pyramid is both a work of art and a giant sundial with the southern arm pointing north-south and set parallel to the earth’s axis of rotation. The two secondary arms also have astronomical significance as one is aligned toward the point on the horizon where the Sun rises and the other to where it sets at the time of the Summer Solstice, which is the longest day of the year.


The huge size of the Solar Pyramid allows us to draw a dial that can be read for every day of the year, although to avoid clutter, only the months of the year are marked. This means that it is possible to read Greenwich Mean Time directly from the dial as the shape of the hour and minute markers allows for the Equation of time. The markings also allow for the fact that the dial has a slope of 1:50 to allow rainwater to run off.

The dial also shows the time of sunrise and sunset at the Solar Pyramid and illustrates the difference in the number of hours of daylight from summer to winter.

When the dial is designed to show the time for each day of the year, it is no longer necessary to have the gnomon pointing parallel to the Earth’s axis of rotation. For example, the gnomon could be vertical or correspond exactly to the angle defined by a 3:4:5 right angle triangle, as does Kahfre’s pyramid at Giza, one of the the original inspirations for the project. We have decided to follow conventional sundial design, uniquely anchoring the angle of the Solar Pyramid to its latitude. The design of the dial is unique to both latitude and longitude.


The unique design and enormous size of the dial will provoke many questions, which provide educational opportunities. These will lead people to a greater awareness of the daily rotation of the Earth, its annual orbit of the Sun and how this provides us with seasons as well as the meanings of words such as solstice and equinox.

For example the ‘squiggly’ hour lines on the dial are caused by the combination of the Earth’s varying speed, as it orbits the Sun on an elliptical path and the tilt of its rotation axis, which causes our seasons.

The shape and orientation of the Earth’s orbit and the tilt of the Earth’s rotation axis are encoded in the design of the dial. These all change very slowly with time and provide an ultimate limit on the accuracy of the dial. It is this variation that has been responsible for the steady ebb and flow of ice ages over the last three million years.

The ‘Time for All’ Fundraising Initiative

From the day of the project’s completion the public will have the opportunity to purchase their own unique moment on their chosen day, dedicated on-site and interactively online. Those special days marking an occasion, a commemoration, a celebration or simply an expression of support.

All proceeds will go to causes of national concern, with special emphasis given to the environment and the younger generation who will inherit a challenging future.