High Cup Nick, bridleway right around the valley.

Twistleton Scar, bridleway goes right past.

What else?

The UK is full of amazing geology but spotting it and then knowing its significance is all a bit relative, it all depends upon how subtle your eye is and your background. South shore area of Loch Torridon (amongst a number of other places) displays an exhumed landscape. It’s really, REALLY old and proper good. Herbert’s Quarry in Carmarthenshire (like many other places) is full of coral fossils. Cwm Idwal is a beautiful geological and geomorphological landscape plus some incredibly rare botany. The story the Aberystwyth cliffs tell is very dramatic. I could go on and on and on.
Where I went to school in Essex I would stop on the cross country ru course, sit down and not move until I’d found a fossil. I seldom had to sit around for more than a minute or two. Perhaps not ‘in your face’ landscape drama but pretty damn cool- a 165 million year old fossil just lying there and then picked up by little old me.

Stair Hole/ Lulworth Cove? Malham Cove? All of Scotland. All of Wales. I’ll stop now, there is just too much to choose from once you are on the left of the Tees-Exe line.

I’m a geologist btw, I o

Ok let me try and propose some criteria.

• ‘in your face’ landscape drama, as you said, or smaller scale
• can be legally ridden to, or at least without a ridiculous level of cheekiness
• using a MTB to access it significantly improves the experience, e.g. it’s not right by the road

Minninglow, neolithic burial mound, just off the High Peak Trail.

Mam Tor landslide and broken road.

The wangie.

Not sure how you would make an interesting ride out of it though…

Maybe try riding through it until you handlebars get stuck?

Cave country, e.g. Hull Pot, or the line of high entrances (Rowten, Swinsto, Bull, Yordas) that you pass along the Turbary Road on the west side of Kingsdale. Dramatic when they’re taking water after heavy rain.

But I’ve always liked the intersection of man and nature at old industrial areas, now abandoned and fading back into the landscape – exploited for geological reasons (mining, quarrying) and, handily, accessed by plentiful tracks. The moors north of Gunnerside and Reeth are a good example.

View from Dumyat back over Stirling and the carse is of three volcanic plugs.

Oooh, I can see the pub office from here.

Geology is great but a stopping at everything bike ride around Rousay blows the mind.

If you’re ever down in Somerset, Cheddar Gorge is a lovely ride and the whole of the Mendips are pretty much a geological feature.

They’re not geological, but Priddy Nine Barrows are worth a look as is Ebbor Gorge. You can drop down onto the levels for Glastonbury Tor.

Here y’go, there’s a bike in there if you look hard enough.

Devils Punchbowl in Hindhead, Surrey Hills. Formed by spring water eroding the sandstone. You can ride round the edge to Gibbet Hill and look east along more of the Greensand ridge, (Pitch Holmbury and Leith Hills), south east across the Weald to see about 40- 50 miles of the South Downs, north to see the North Downs (and London in a clear day).

Maybe not as knock-your-socks-off spectacular as some of the others, but a definitely a decent view of a large scale geological feature!

https://en.m.wikipedia.org/wiki/Weald%E2%80%93Artois_Anticline

The Ludlow Anticlyne – a major feature where the Wenlock Edge to Radnorshire Silurian limestone ridges kink throwing up Bringewood. Lots of exposures due to quarrying and road building.  At primary school, the status symbol was finding a trilobite.

The rock can weather quickly – that mud on your tyres could be 420 million year old seabed silt.

I was riding up in the north west of Scotland this weekend and in the youth hostel at Gairloch I bumped into a guy from the Edinburgh Geological Society who runs geology themed walking holidays. That area is perfect for it – great riding and amazing geology, but you do have to know what you’re looking for.

Take Fisherfield – you’ve got some of the oldest rocks in the world (Lewisian Gneiss), then lovely red Torridon Sandstone sat on top of it and then on top of that quartzite caps that burn red in the light of a sunset. Amazing stuff, and the gneiss has big massive lumps of all sorts of stuff in it, and there’s also the Moine Thrust which has left an escarpment further up some of the glens. Some of the rocks you see in the rivers are fascinating – they really demonstrate just how violent the geological processes round there are.

But, while it’s a spectacular landscape, it takes some geological knowledge to enjoy it (I am a geologist) and you don’t really get the big single exciting feature to marvel at.

I’ll also throw Edinburgh and the Pentlands into the mix. Riding the Edinburgh Seven Hills you’re riding a group of extinct volcanoes with some really great features.

The Fife Coastal Path goes by some good caves and the Rock and Spindle, a volcanic plug sitting on a beach.

Scotland’s just full of stuff.

Caer Caradoc, The Lawley and (a bit further away) The Wrekin/Ercall.
A linear feature of 3 hills, all roughly 650m years old, consisting of big lumps of ash and lava from dormant volcanic vents. Not volcanoes as such, but not far off.
From any of them, you can also see Wenlock Edge as mentioned by @fasgadh above, which represents the exposed edge of a Silurian limestone bed, not quite so old. There’s a bridleway runs along quite a lot of the length of it, with some bits of cheeky, granted.

Oh, and the Quirang! And the Old Man of Hoy!

In England, there are obvious things in the Peak like the landslip on Mam Tor, Winnat’s Pass, Cavedale and Striding, Froggatt and Derwent Edges. All, probably with the exception of Winnat’s, improved by a bike ride.

We’re very lucky here because of how our geology changes quickly over small areas. When I was touring on the bike through the Baltic States, it was just sand for three countries.

Mam Tor landslide and broken road.

The other interesting aspect of Mam Tor is that it’s the site of a Bronze Age/Iron Age hill fort and both the ramparts and small, oval platforms that once housed round houses are still visible.

Old Man of Hoy should obviously be Storr…

There’s the old open cast mine (Odin Mine?) just where the old road ends at the foot of Mam Tor.

Hutton’s (first) Unconformity, Lochranza, Isle of Arran. Unfortunately it doesn’t score too highly on the dramatic landscape chart, but according to geologists it’s very significant.

The Brecon Gap ride is great for this, the view north down the glacial valley from the gap is spectacular. A cheeky detour gets you up to the summit of Pen y Fan to see the ripply sandstone which used to be at the bottom of the sea and a great view of Cwm Llwch glacial lake.

Trotternish on Skye

The overhanging cliffs of Sròn Uladail on Harris probably meet all 3 of the OPs criteria.

Ivinghoe Beacon – a high point on the edge of the Chilterns with views over flat plain to the north and west. Remains of an iron age hillfort on the top – not surprising as it’s just by The Ridgeway.

It’s not strictly legal to cycle to the top (and I’ve never made it without having to push the last few yards) but the base is fine.

Huntsman’s Leap and Elegug Stacks in Pembs. There is more cracking limestone coastal stuff here but photos won’t post.

The other interesting aspect of Mam Tor is that it’s the site of a Bronze Age/Iron Age hill fort and both the ramparts and small, oval platforms that once housed round houses are still visible.

Pfft come to the borders, every bloody hill had a hill fort.

If you go road rather than MTB, Haytor has one of the best climbs in the country, nice to ride around and over to Hound Tor and loop back down to Widdecombe. Come back up to Haytor again If you really fancy some more hill action. Lovely views down the Teign Estuary to the sea.

Bow Fiddle rock on the Moray Coastal Trail.

The Ardnamurchan Crater.  Now that one really shows up on google satellite view or OS 50k mapping, as well as when you’re there, nearly surrounded by the escarpment.  Nearby, Sanna beach (most westerly on mainland UK) and Camus nan Gael, overlooked by another volcano, Ben Hiant.

Perhaps starting at Kilchoan, you could build up an interesting, challenging circular route to most of these by taking in the trail sections along the north coast, Glendrian, Fascadale, then via Kilmory and Ockle.  It all connects up and would be a great day out.  There are gaps on the OS 50k but the trail’s there on the ground.

Does anyone know if the GlenBorrowdale – Acharacle trail goes on a bike?  that might be better than the road from Acharacle to Salen and along to Kilchoan.  @Dovebiker ?

I’ve done all that (a lot just within the last six weeks). Great walk, so-so on a bike. While much of it is rideable, it’s tipping just over the hikeabike threshold for me. Might be different for others. One of those areas where the bike would limit rather than facilitate travel.

Does anyone know if the GlenBorrowdale – Acharacle trail goes on a bike?

It does. Bit boggy in some places. There have been some access issues at the GB end so something to be aware of. I’ve done the loop of Kilchoan – Glenborrodale – Ockle – Kilmory, returning via the minor road.

Purbeck Ridge from Studland to Corfe Castle and beyond.

Geologically interesting as the cut through the chalk ridge at Corfe happened during the last ice age when the chalk was frozen solid.  Ordinarily, with chalk being porous, the water would soak into it rather than erode it.

Lots of bridleway choices to take you along to Lulworth Cove too.

Rides in the Longmynd-Church Stretton area are within an active fault system within Precambrian-Ordovician age rocks. The faults are mainly the incised valleys. As someone mentioned above, volcanic edifices on the fault gave rise to the Wrekin etc.. during the Caledonian orogeny (I think). So, fill your boots!

Local to me is the Glasshouse Mountains. They’re not actually the plugs from volcanoes, but vents that have remained after the surrounding land has eroded around them. Highest is Mt Beerwah on the right (~500m).

You don’t have to ride to get this view, but it’s more fun and rewarding if you do.

Another ‘mundane’ one…

Back in Dorset all of the above but I’ll add Old Harries Rocks. A sea stack that can be easily combined with an excellent bike ride.

Hodge Close in the Lake District including Catherdral Cave. Apparently there’s a section of cave that can be ridden through. I have walked it.

One of the mags (probably Brant) took bikes through Long Churn BITD, although I wouldn’t recommend it. If I recall correctly he also abseiled down Malham Cove with a bike. Not sure what tyres it had on.

I was on a work trip to Palo Alto a while ago, and borrowed a bike to ride down a local trail. Turned out later it was the trace of the San Andreas Fault. Which I had not noticed at all. Bit embarrassing for a geologist.

I had seismology lectures from a Californian woman. She had left as she felt the earth quake risk was so high. Particularly as so much key infrastructure, like hospitals, are on the fault

I’ll add North wales llanberis and Bleanau Ffestinog for the amazing slate quarries

The Brecon Gap ride is great for this, the view north down the glacial valley from the gap is spectacular.

It certainly is.