AttractionEnglish Heritage

Grime's Graves - Prehistoric Flint Mine

Thetford, Norfolk

Britain's only accessible Neolithic flint mine, with open Breckland heath above ground for your dog while you climb nine metres down into Pit One.

There is nowhere else in Britain you can climb down into a Neolithic mine, which makes this genuinely unusual. The surface is a lunar landscape of more than 430 shafts and quarries pocking the Breckland heath, named Grim's Graves by the Anglo-Saxons, meaning the pits of the pagan god Grim, because they had no idea what they were. Only when one was excavated in 1870 were they identified as flint mines dug around 2650 BC.

Whilst you descend nine metres by ladder into Pit Number 1, where film projections put you among the people who worked the seam, your dog stays up top, and the surface is the other half of the visit: open Breckland heath, sandy soil, heather and pine, with the shaft hollows to wander between and a lot of space.

Dogs are allowed on leads, though not down the mine, so plan for that. Free parking for 50 cars sits 500 metres from the entrance. There is a café, shop, toilets, exhibition and picnic seating. Ministry of Defence training country is nearby, so pay attention to signage.

At a Glance

Dog Access: On-lead in the grounds; Dogs are allowed on leads.
Site Type: Prehistoric Site
Entry: £9.35 adult; £4.67 child · £23.37 family
Members: Free for English Heritage members
Facilities: Café / restaurant, Exhibition, Gardens, Parking, Picnic seating, Shop, Toilets, Wheelchair access
Telephone: 0370 333 1181
Parking: Free parking for 50 cars 500m from the site entrance. There’s additional charged parking at Lynford Stag picnic site, not run by English Heritage.

English Heritage Membership

Planning Your Visit

Opening times

Monday: Closed
Tuesday: Closed
Wednesday: 10:00 - 17:00
Thursday: 10:00 - 17:00
Friday: 10:00 - 17:00
Saturday: 10:00 - 17:00
Sunday: 10:00 - 17:00

Opening times and prices were checked on 26 August 2026 and are subject to change, and some sites close for events or over winter. Confirm on the English Heritage site page before you travel.

Frequently Asked Questions

Is Grime's Graves - Prehistoric Flint Mine dog friendly?
Dogs are welcome at Grime's Graves, though they must stay on leads and aren't permitted down into the mine itself. That said, the surface is a genuinely rewarding place to explore with a dog — open Breckland heath with heather, sandy soil, pine trees, and more than 430 ancient shaft hollows to wander between.
Are dogs allowed at Grime's Graves - Prehistoric Flint Mine year round?
The listing doesn't specify any seasonal restrictions on dogs, but it's worth checking English Heritage's opening times before you visit, as the site's hours may vary by season. The outdoor heath area is the main space for dogs, so weather is worth factoring into your plans too.
What should I know before visiting Grime's Graves - Prehistoric Flint Mine with my dog?
The key thing to plan for is that dogs can't go down into Pit Number 1, so if there are two of you, one person can take the nine-metre ladder descent while the other explores the surface with the dog — which is very much half the visit in its own right. There's free parking for 50 cars about 500 metres from the entrance, plus a café, toilets, and picnic seating on site. The area is also near Ministry of Defence training land, so keep an eye on any signage as you explore.

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Lynford

Thetford IP26 5DE

52.4775, 0.6722

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