Like many other mints, the Royal Mint issues bullion coins in precious metals, having much higher intrinsic value than their face value. The five ounce (5 oz) silver coins are denominated as ten pounds (£10).
The coins are legal tender but are not intended for circulation. They are targeted at bullion investors or collectors who appreciate the special editions as pieces of art. The coins are typically "one-year" types usually issued in parallel with smaller denominations with the same reverse designs.
This commemorative five ounce silver coin was issued to commemorate the Centenary (100th Anniversary) of the First World War, one of the worst conflicts in human history.
The bleak landscape on the reverse side of the coin was designed by world-respected sculptor, James Butler. The inspiration for this design came from Butler’s years of research into the First World War for the 42nd Rainbow Division, for whom he created a memorial inaugurated in 2011. It includes a haunting scene depicting a path of duckboards flanked by war-ravaged trees. Along the muddy ground, we see the faint outlines of indistinct figures - soldiers that laid down their lives, now lost in the mud, with no hero’s grave. The commemorative years 1914 - 1918 are placed above the primary design, with no other inscription. | 
Search for United Kingdom: Silver Five Ounces 2015 World War One on eBay 