Modern electricity-producing windmills can appear quietly graceful from afar, sleek and spindly apparitions with thin blades turning lazily in the sky. To truly appreciate the size and power of these machines you need a vantage point typically only accessible to wind turbine mechanics. The wind turbine at the Green Britain Centre makes that perspective available to the public.

Built in 1999, the Green Britain Centre’s wind turbine was the United Kingdom’s first megawatt-class windmill. With a hub standing 67 meters high and rotors measuring 66 meters in diameter, it boasts a power capacity of 1.5MW. It is also the only wind turbine in the UK which visitors can ascend to reach a viewing platform — designed by Sir Norman Foster, the same architect who designed New Wembley Stadium — located just under the generator.

The climb involves 305 steps up a tight spiral staircase; once at the top, the tower moves quite a bit and the windmill’s operation is quite noisy. But the platform also affords the rare view of rotor blades swooping past the glass enclosure, as well as a 360-degree panoramic view of the surrounding Norfolk countryside.

The Green Britain Centre features other exhibits relating to green energy, transportation, and food, such as the world’s fastest wind-powered vehicle, the United Kingdom’s largest solar tracker, and organic gardens.

Update May 2019: The Green Britain Centre is now closed to the public and for any future events and bookings.