A stone wall with a metal bracket marked with the broad arrow and OS BM G3575.

A ridiculously-happy, middle-aged man, sporting sunglasses, shorts and a gilet, points at a short, concrete pillar surrounded by green railings.

A concrete pillar surmounted by a circular brass/copper plaque sits within a patch of grass with dandelions. The words HEIGHT ABOVE DATUM and 797.28 FT are embossed on the top of the plaque and in the centre is a stud.

Two children, a girl and boy, stand in front of a railed enclosure containing a concrete pillar. The boy is holding on to a lamppost with a square ‘no through road’ sign and a circular 30mph speed limit sign.

An absolute corker for #BenchMarkMonday

First up a nice flush bracket G3575 located in a #WorldHeritageSite - Mill Road, Cromford just opposite Arkwright’s Mill.

And the pièce de résistance the Fundamental Bench Mark at Riber, Derbyshire - 797.28 ft AOD. A first for Alice, Sid and me.

Flush Bracket Bench Mark S5429

Trig Pillar TP1879 - Callow Hill.

Looking towards Flounders Folly

Flounders Folly which was an OS Trigonometrical Station in the C19th

For #benchmarkmonday Flush Bracket S5429 that is set into Trig Pillar TP1879 on Callow Hill that overlooks Craven Arms in Shropshire. The Pillar's neighbour is Flounders Folly tower that was an OS Trigonometrical Station in the C19th

A photograph of an ordnance survey rivet embedded in a stone in the NW corner of St Bartholomew’sChurch, Chosen Hill, Gloucs.

An extract from the OS benchmark map showing the precise location & height of benchmark 145.740m

#BenchmarkMonday
St Bartholomew’s Church, Churchdown,Gloucestershire.

2/ More suggested hashtags to join on a Monday

#MistyMonday

#MapMonday
#BenchmarkMonday

#MilestoneMonday

#MountainMonday

#MarketMonday

#MaritimeMonday

#MonumentMonday
#MemorialMonday
#MementoMoriMonday

2 of 8   #MondayHashtags

Monday
#AllMetalMonday
#BenchmarkMonday
#BlueMonday
#BrutalMonday / #MondaysAreBrutal
#ClassicLitMonday
#JadeMonday
#MagentaMonday
#MallardMonday
#MammalMonday
#ManholeCoverMonday
#ManuscriptMonday
#MapMonday
#MarbleMonday
#MaritimeMonday
#MarketMonday
#MedievalMonday
#MementoMoriMonday

Good morning all. Happy #BenchmarkMonday from St Peter and St Paul Church, Edenbridge.
#Honeypot100 #EdenValleyWalk #Walking

Horizontal line on damaged bricks of a house.

Cut benchmark on a bridge over a stream, half a metre below road level.

Cut benchmark on the lower stone courses of a red brick barn.

This weeks Tough Datum Hunting included cut marks on damaged bricks in Kettering, a scramble down to a stream for a bridge near Market Bosworth, and a surprisingly well preserved mark on the stone course of a barn in Barton on the Beans.

#BenchmarkMonday

#AllMetalMonday
#BenchmarkMonday
#BlueMonday
#BrutalMonday / #MondaysAreBrutal
#ClassicLitMonday
#JadeMonday
#MagentaMonday
#MallardMonday
#MammalMonday
#ManholeCoverMonday
#ManuscriptMonday
#MapMonday
#MarbleMonday
#MaritimeMonday
#MarketMonday
#MedievalMonday
#MementoMoriMonday

Seems there's a whole community for this hobby - I'll have to start getting involved! 😊👍

#BenchmarkMonday

2/ More suggested hashtags to join on a Monday

#MistyMonday

#MapMonday
#BenchmarkMonday

#MilestoneMonday

#MountainMonday

#MarketMonday

#MaritimeMonday

#MonumentMonday
#MemorialMonday
#MementoMoriMonday

2 of 7   #MondayHashtags

Happy #BenchmarkMonday from Nutley, St James the Less.

#BenchmarkMonday 9.175m on the gateway of Christ College, Cambridge

OS benchmark cut on the rendered wall of a ruined building

Bah. Found this benchmark over the weekend and forgot to post it on #BenchmarkMonday ( #geodesy ). It is this one: www.bench-marks.org.uk/bm229665

Happy #BenchMarkMonday Here’s a cracker at The Anchor,Bankside, That London. Check it out and treat yourself to a beverage

Cut benchmark on a red brick wall of Siddals Road

Siddals Road in Derby is perhaps better known for its pub, the Alex’, but opposite you can find an Ordnance Survey Benchmark.

#BenchmarkMonday

Monday
#AllMetalMonday
#BenchmarkMonday
#BlueMonday
#BrutalMonday / #MondaysAreBrutal
#ClassicLitMonday
#JadeMonday
#MagentaMonday
#MallardMonday
#MammalMonday
#ManholeCoverMonday
#ManuscriptMonday
#MapMonday
#MarbleMonday
#MaritimeMonday
#MarketMonday
#MedievalMonday
#MementoMoriMonday

2/ More suggested hashtags to join on a Monday

#MistyMonday

#MapMonday
#BenchmarkMonday

#MilestoneMonday

#MountainMonday

#MarketMonday

#MaritimeMonday

#MonumentMonday
#MemorialMonday
#MementoMoriMonday

2 of 7   #MondayHashtags

Good morning all. Happy #BenchmarkMonday from St Luke's, Chiddingstone Causeway. It was built in 1897–1898 to a design by John Francis Bentley in a loosely Decorated Gothic Revival style, replacing a tin tabernacle.

An OS Flush Bracket set into a retaining wall on the slope down to the basement of the British Museum

OS Flush bracket bench mark set into the wall behind a handrail. A plaque below reads. “THIS BRACKET LI IS 86.901 FT ABOVE MEAN SEA LEVEL NEWLYN”

OS Flush Bracket with the designation LI (L1) set into a retaining wall on the South East wing of the British Museum, London

A lovely flush bracket for #BenchMarkMonday at the British Museum, That London. Not quite visible from the publicly accessible part of the entrance courtyard but as I was in a meeting with staff I was able to get up close and personal.

Monday
#AllMetalMonday
#BenchmarkMonday
#BlueMonday
#BrutalMonday / #MondaysAreBrutal
#ClassicLitMonday
#JadeMonday
#MagentaMonday
#MallardMonday
#MammalMonday
#ManholeCoverMonday
#ManuscriptMonday
#MapMonday
#MarbleMonday
#MaritimeMonday
#MarketMonday
#MedievalMonday
#MementoMoriMonday

2/ More suggested hashtags to join on a Monday

#MistyMonday

#MapMonday
#BenchmarkMonday

#MilestoneMonday

#MountainMonday

#MarketMonday

#MaritimeMonday

#MonumentMonday
#MemorialMonday
#MementoMoriMonday

2 of 7   #MondayHashtags

Good morning all. Happy #BenchmarkMonday from St Nicholas Church, Sevenoaks.

#BenchmarkMonday 32.551m aOD on St George's Church, Thriplow

Cut Ordnance Survey Benchmark low down on a low wall near Peterborough’s iconic Blue Railway Bridge.

Entrance to the Session House, formerly a Gaol, then a pub, now an NHS property. Benchmark to the left of the door.

Ordnance Survey Cut Benchmark and Bolt in the stone.

Plaque by The Peterborough Society for The Session House.

Todays tough, and not so tough Datum Hunting in Peterborough.

#BenchmarkMonday

2/ More suggested hashtags to join on a Monday

#MistyMonday

#MapMonday
#BenchmarkMonday

#MilestoneMonday

#MountainMonday

#MarketMonday

#MaritimeMonday

#MonumentMonday
#MemorialMonday
#MementoMoriMonday

2 of 6   #MondayHashtags

A bench mark carved onto a corner stone of the tower of St. James’ church, Piccadilly.

An oval plaque, set into a brick wall commemorating the restoration of St. James’ Church, Piccadilly

One for #BenchMarkMonday on the tower of St. James’ Church, Piccadilly. 17.681m aod. Also nice plaque commemorating the restoration of the church following damage from enemy action during the Second World War.

I’m going to also count the cover of the Earth Rod for #JustAnotherManholeMonday

#AllMetalMonday
#BenchmarkMonday
#BlueMonday
#BrutalMonday / #MondaysAreBrutal
#ClassicLitMonday
#JadeMonday
#MagentaMonday
#MallardMonday
#MammalMonday
#ManholeCoverMonday
#ManuscriptMonday
#MapMonday
#MarbleMonday
#MaritimeMonday
#MarketMonday
#MedievalMonday
#MementoMoriMonday

Good morning all. Happy #BenchmarkMonday from St.Peters Church, Pembury. The Old Church dates back to around 1085, and much of it was rebuilt in 1337.

#SluiceValveSunday and an early #BenchmarkMonday

A brick wall with an Ordnance Survey Bench Mark highlighted in red chalk. Royal Hospital Building, junction of West Road and Royal Hospital Road. AOD 7.294m

Stone wall with ornate railing. A faded OS Bench Mark. Can be seen on the wall. BM @19.505m AOD

A couple of beauties for #BenchMarkMonday Royal Hospital Chelsea (Red Brick) and Burlington House, Piccadilly