SecretLeeds - History, culture and architecture in Leeds

Does anybody know what this peculiar mark is? It’s carved into the stone wall on Dock Street, just above street level.The buildings around there have all sorts of unusual features – old loading bays up on the first floor for example, with what look like struts or supports for pulleys and lifting equipment. This thing looks almost Masonic though!

It looks like an arrow pointing to the level that the water probobaly once reached

It's an Ordnance Survey benchmark that indicates a known vertical elevation. Surveyors would place a levelling rod (bench) into the horizontal groove, which is highlighted by the three arrows underneath. Wikipedia explains the whole thing a lot better than I can.Once you start to look for them they start to appear all over the place.

I found this one on Great George Street this morning, outside Carpe Diem.

Here's a nice concrete example out in the sticks with the serial number on

Ordance survey bench mark s3862

That looks familiar phil!There must be a website somewhere where these are all listed.

If there isn't, then let's make this that website.

Sounds good to me Rik mate!!

if you look on OS sheets you will often see benchmarks detailed with their level above ordanance datum (AOD). funnily enough although the OS sheets are pretty accurate plan wise, many of the benchmark levels shown are hopelessly out due to not being re-surveyed with modern methods and movement of the structure its on. The ordnanace datum used is mean sea level at the harbour at Newlyn, Cornwall.the one pictured on the concrete pillar - this could be triangulation point - does it have bronze plate on the top for setting up a theodolite/total station? they are used as fixed reference points. there's one in the field behind the water tower at Garforth. Hi everyone by the way, im new (as i guess are most people!)