![A serious challenge, trig 642 is, despite its modest height, quite possibly one of the most demanding trig pillars to bag, if you stay true to the way it would be reached A serious challenge, trig 642 is, despite its modest height, quite possibly one of the most demanding trig pillars to bag, if you stay true to the way it would be reached](https://getoutside.ordnancesurvey.co.uk/site/uploads/images/assets/Thumbnails/new%20adventure%20thumbs/Brecon%20Beacons.png)
A serious challenge, trig 642 is, despite its modest height, quite possibly one of the most demanding trig pillars to bag, if you stay true to the way it would be reached
![Tested to destruction: Ex-SAS officer reveals the terrifying selection process for special forces | Daily Mail Online Tested to destruction: Ex-SAS officer reveals the terrifying selection process for special forces | Daily Mail Online](https://i.dailymail.co.uk/i/pix/scaled/2013/07/16/article-2364723-1AD02536000005DC-320_310x189.jpg)
Tested to destruction: Ex-SAS officer reveals the terrifying selection process for special forces | Daily Mail Online
![SAS test march officer didn't know of 'hottest day' predictions, inquest told | Military | The Guardian SAS test march officer didn't know of 'hottest day' predictions, inquest told | Military | The Guardian](https://interactive.guim.co.uk/uploader/embed/2015/06/sas_brecon_beacons_map/giv-21277s5ha7vXGm7Sm/img/SAS_Brecon_Beacons_RouteUPDATE-3-0-0.png)