Marsh harrier in flight fighting over prey

Lade Pits and the Denge Sound Mirrors

Lade Pits is a restored gravel quarry which is now part of the RSPB Dungeness Nature Reserve.

The history of Lade Pits

The 70 hectare site previously produced over four million tonnes of sand and gravel for local construction projects, and was handed over to the RSPB in 2015 by Cemex, to be managed as a nature reserve. This bio-diverse habitat is already home to an array of outstanding wildlife such as marsh harriers, great white egrets, medicinal leeches and the rare Sussex emerald moth. Habitats include rare vegetated shingle, fen, reedbed and open water. The site benefits from Site of Special Scientific Interest (SSSI), Special Area of Conservation (SAC), Ramsar and Special Protection Area (SPA) status.

Lade Pits is a unique site for history as well as wildlife, as it contains three Scheduled Ancient Monuments, which are of international significance. The Denge Sound Mirrors (also known as the Acoustic Mirrors or Listening Ears) are three concrete structures which range in size from 20 to 200 feet.

They were built between 1928 and 1935 as part of Britain's national defence strategy. The low lying Romney Marsh was well suited for the placement of the Mirrors which were designed as early warning systems to pick up the sounds of approaching enemy aircraft coming over the English Channel. But the innovative technology was soon superseded by the invention of radar before the start of World War II. However, time spent constructing the Sound Mirrors was not wasted, as the technology used to create these led to developments of other aircraft detection systems.

Denge Sound Mirrors

Want to visit?

Lade Pits is open all year round to visitors. We would recommend the use of the entrances from Taylor Road, Leonard Road or Seaview Road. There is no car parking on site, so please use the public car parks on the seafront (Coast Drive/The Parade). Please use the designated trails around the site.

This nature reserve is protected under SPA, SAC, RAMSAR and SSSI designations. Activities that disturb or damage wildlife (including fishing, boating or swimming) are strictly prohibited on the reserve. Dogs are welcome but must be kept on a lead and picked up after. To protect them from damage, the Sound Mirrors are located on an island in the middle of the reserve, restricted by a locked swing bridge and can only be accessed under supervision. However, they can be seen clearly from the bank.

Special events, where you can get closer to the Sound Mirrors are run throughout the year. An open day is run annually in the summer.

Guided tours and photography days are run between August and December. Please see our events page for more information. If you wish to arrange a group visit (minimum of 25 people) please email

Want to help?

The RSPB maintains Lade Pits as a local nature reserve which the community can enjoy. If you would like to become more involved, we are always looking for volunteers who can help us manage and maintain the site.

Please email if you are interested in volunteering with us to help keep this reserve a unique and special place that the community can be proud of!

Filming at Lade Pits

The Sound Mirrors are an iconic part of UK history, and many artists have used these to create an amazing backdrop in films, photo shoots and music videos. We allow the responsible use of this unique site, under strict supervision, for a wide range of commercial activities at a competitive fee.

To use the area for any commercial filming or photography, please send enquiries to

We ask for at least 3 weeks’ notice from the date of your enquiry to the date of your activity. Requests with less than 3 weeks’ notice prior to your suggested date of activity will not be considered.

The minimum charge for the site per day (8 hours) is £750 plus VAT. Site hire will be priced according to the size, timing and complexity of the activity. For a tailored quote please contact

The company must provide Risk Assessments and a Public Liability Insurance Certificate to the value of £5 million minimum. Access can then be approved subject to completion of the RSPBs filming agreement.

Access for commercial activity cannot be granted during our closed season between 1st April and 1st July, as our priority is to preserve the habitat and reduce disturbance for breeding wildlife.

Commercial film or photography and access the Sound Mirrors without knowledge and approval from the RSPB is strictly prohibited. Disturbing the SSSI habitat could lead to a fine of up to £20,000 and it is a criminal offence to damage a Scheduled Monument under the Ancient Monuments and Archaeological Areas Act 1979.