Like many other mints, the Royal Mint issues bullion coins in precious metals, having much higher intrinsic value than their face value. The one ounce (1 oz) silver coins are denominated as either two pounds (£2) or five pounds (£5), depending on the occasion.
Initially, these were only of the Britannia type, but in 2015 the Royal Mint started to use the format for coins with other types of reverse designs, celebrating various aspects of British heritage.
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.
This coin is the second issue from a series of silver coins known as the Landmarks of Britain.
The Royal Mint says:
"Instantly recognisable to people from across the world, Tower Bridge rises above the river Thames, an integral part of the London skyline. An outstanding example of nineteenth-century design and engineering, people still marvel at the bridge when it is raised to let tall ships pass upstream.
Created by Laura Clancy and Glyn Davies of The Royal Mint Coin Design team, their interpretation of this iconic building is highly impressionistic." | 
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