At the time of decimalisation in 1971, the United Kingdom Crown coin (equal to 5 shillings) was redenominated as a 25p coin and pieces struck prior to 1990 - all the way back to 1818 - continue to be legal tender for that amount. The old denomination had been a regular circulating coin in the 19th century, but in the 20th century it became more of a commemorative denomination.
The Royal Mint continued issuing commemorative coins in the same format - using the traditional coin dimensions, but in copper-nickel. These were initially also denominated as 25 pence but the "Crown" was changed in 1990 to a commemorative £5 (five pound) coin, having the same dimensions and weight but with a face value twenty times as great.
The denomination is used to mark special occasions, usually royal in theme, rather than for use in general circulation. Although not circulating, these coins are legal tender.
This £5 Crown-sized coin is part of a four-coin set of silver coins called "Portraits of Britain", which is the third in a series of sets issued over several years. The 2017 set features iconic buildings from around the United Kingdom; this coin shows Edinburgh Castle.
Edinburgh Castle is a historic fortress which dominates the skyline of Edinburgh, the capital city of Scotland, from its position on the Castle Rock. Archaeologists have established human occupation of the rock since at least the Iron Age, although the nature of the early settlement is unclear.
Designed by Royal Mint engravers Laura Clancy and Glyn Davies, each attraction is viewed as though through the eyes of a visitor, giving the coins the feel of an impressionist painting, enhanced by the trichromatic colour-printing.
The coins were issued in Proof FDC grade in sterling silver only. | 
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