Contributions of the group Benchmark hunting

Spy Satellite Target

nobody@ipernity.com (Robert Swanson) — Tue, 31 Mar 2026 15:31:55 +0000

Taken in the desert near Casa Grande, Arizona. These markers are located close to the RV park where we spent many winters.

The "target" is a group of concrete pads in that shape. There is a benchmark in the exact center. The operators of the spy satellites would take photos of these markers, and then check their locations against the exact positioning of the benchmark.

Image taken with phone and processed with GIMP.

Hoover Dam Survey Benchmark

nobody@ipernity.com (Robert Swanson) — Sun, 25 Jan 2026 22:05:47 +0000

Robert Swanson has posted:

Taken during our 2012 visit.

Hoover Dam Survey Benchmark

nobody@ipernity.com (Robert Swanson) — Sun, 25 Jan 2026 22:05:48 +0000

Robert Swanson has posted:

Taken during our 2012 visit.

hca[25] - OS mark {1 of 2}

nobody@ipernity.com (StoneRoad2013) — Fri, 11 Jul 2025 20:49:31 +0000

StoneRoad2013 has posted:

Spot the OS benchmark !

The bolt is just to the right of the line - see Note

further info

www.bench-marks.org.uk/bm25251

whn - watchtower [HWW]

nobody@ipernity.com (StoneRoad2013) — Sun, 07 Apr 2024 16:47:52 +0000

StoneRoad2013 has posted:

Weathered sandstone blocks in the Watchtower on the Old Quay, Whitehaven.
Note the one block that's been laid "against" the grain ...
The "35" plaque refers to points of interest on a self-guided walking route around the town, the details are summarised in the main plaque.
Also has an Ordnance Survey "benchmark"
[previously uploaded on 13Aug2024, but not published at that time]

E2A - Benchmark dates to the primary levelling survey of the UK done in 1840 - 1860 ...
www.bench-marks.org.uk/bm30133

IoM[2] - Snaefell's six kingdoms ...

nobody@ipernity.com (StoneRoad2013) — Sun, 30 May 2021 22:06:44 +0000

StoneRoad2013 has posted:

DJC at the viewpoint marker, beyond is a trig point [pillar] and one of the radio masts [NATS].

On a clear day like this, one can see six kingdoms - The Isle of Man, England, Wales, Scotland, Ireland and Manannan [or Neptune].

hlft[24] - Benchmark

nobody@ipernity.com (StoneRoad2013) — Wed, 19 Jun 2024 19:33:52 +0000

StoneRoad2013 has posted:

Ordnance Survey Benchmark, in very good condition.

Cast brass [?] set into the wall of a shop in Middleton-in-Teesdale.

www.bench-marks.org.uk/bm737

This bench mark was used during the Second Geodetic Levelling, England & Wales [1912 - 1921]. It was included on the Wolsingham to Kirkby Stephen line as "Flush Bracket on N.E. corner of house, junction of Bridge Street and Horse Market, Middleton in Teesdale. " at 755.347 feet above Newlyn datum.

twb[23] - Benchmark

nobody@ipernity.com (StoneRoad2013) — Wed, 30 Aug 2023 10:50:27 +0000

StoneRoad2013 has posted:

An ordnance survey benchmark, cut into the stone base of the wall at Molten.

WD is "War Department" [in the UK, the Ordnance Survey was, historically, part of the War Office, responsible for mapping territory].
This one may be damaged, as the broad arrow should be topped with an horizontal line, which is the levelled "spot height". Otherwise it's the point at which the angled lines meet.
Not quite sure of the meaning for the other marks.

en.wikipedia.org/wiki/Benchmark_(surveying)

twb[23] - Molten

nobody@ipernity.com (StoneRoad2013) — Wed, 30 Aug 2023 10:49:42 +0000

StoneRoad2013 has posted:

Looking closely at walls can tell the observer quite a lot about the history.
This site has seen at least five buildings, including the one currently present.
The base is on the site of "Clifford's Fort"

this is part of "Molten" an art gallery / glass studio / gelato & cafe ...
moltengallerycafe.com/news

Geodesic Centre of Portugal.

nobody@ipernity.com (Dimas Sequeira) — Fri, 16 Sep 2022 15:34:20 +0000

Dimas Sequeira has posted:

The geodesic mark dates back to 1802 and stands on Melriça Peak (592 metres of altitude), not far from Vila de Rei, the head of the council.

Geodesic mark at 1,991 metres of altitude.

nobody@ipernity.com (Dimas Sequeira) — Tue, 17 May 2022 22:48:40 +0000

Dimas Sequeira has posted:

It stands in the middle of a roundabout on the highest point of continental Portugal. Curiously it is accessible by car, unlike many lower mountains.
The highest point of Portugal is located at Pico (a 2,351 metres high peak), at Pico Island, Azores.

OS trig point on The Roaches

nobody@ipernity.com (Francis Taylor) — Tue, 09 Sep 2014 09:45:01 +0000

Francis Taylor has posted:

This benchmark is on the highest point of The Roaches in the Peak District.

Trig Point, Wrekin

nobody@ipernity.com (Old Sea Dog) — Mon, 30 Dec 2019 21:16:07 +0000

Old Sea Dog has posted:

The Wrekin, Shropshire

Trig Point, Wrekin

nobody@ipernity.com (Old Sea Dog) — Mon, 30 Dec 2019 21:16:17 +0000

Old Sea Dog has posted:

The Wrekin, Shropshire

Cairn, Wrekin

nobody@ipernity.com (Old Sea Dog) — Mon, 30 Dec 2019 21:16:24 +0000

Old Sea Dog has posted:

The Wrekin, Shropshire

Mt Olympos VHF repeater

nobody@ipernity.com (SV1XV) — Fri, 09 Aug 2019 08:42:03 +0000

SV1XV has posted:

Antenna mast of an abandoned Hellenic Navy VHF repeater site with a UHF radio link, Mount Olympus, Lesbos Island. (DSCN1312)

This work is licensed under a Creative Commons Attribution 4.0 International License.

20120817-P8170082

nobody@ipernity.com (SV1XV) — Tue, 09 Sep 2014 03:32:29 +0000

SV1XV has posted:

Private trig benchmark at Kotzia Squate, Athens. (P8170082)

This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.

20130409-0050

nobody@ipernity.com (SV1XV) — Tue, 09 Sep 2014 03:32:34 +0000

SV1XV has posted:

This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.

20130905-AgMeletiou

nobody@ipernity.com (SV1XV) — Tue, 09 Sep 2014 03:33:01 +0000

SV1XV has posted:

(P9050049)

This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.

Kifissia benchmark

nobody@ipernity.com (SV1XV) — Sun, 18 Jan 2015 09:57:14 +0000

SV1XV has posted:

A rusty benchmark of the Hellenic Mapping & Cadastral Organisation in Kifissia.

Οργανισμός Κτηματολογίου και Χαρτογραφήσεων Ελλάδος

(DSCN0078)