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 fourth and last in a series of sets issued over several years. The theme of the 2018 set is the British seaside; this coin shows the town of Tenby.
Tenby (Welsh: Dinbych-y-pysgod, meaning fortlet of the fish) is a walled seaside town in Pembrokeshire, Wales, on the western side of Carmarthen Bay. Notable features include 4 km of sandy beaches and the Pembrokeshire Coast Path, the 13th century medieval town walls, including the Five Arches barbican gatehouse, Tenby Museum and Art Gallery, the 15th century St. Mary's Church, and the National Trust's Tudor Merchant's House. Boats sail from Tenby's harbour to the offshore monastic Caldey Island. St Catherine's Island is tidal and has a 19th century Palmerston Fort.
The Royal Mint says:
"The great British seaside: fish and chips, penny slots, and don’t forget your bucket and spade. The daily grind is left far behind, for a little while at least. Four coins celebrate some of our most iconic coastal resorts. By turns traditional, quirky and kitsch, each has its own unique character, evoking fond memories of day trips and family holidays.
Made popular by the Victorians, Blackpool with its famous tower is still a firm favourite today. And a trip to Brighton is not complete without trying to snag a prize on the pier. Colourful huts dot the shoreline at Southwold, the perfect base for day at the beach, while Tenby with its picturesque harbour is very much the jewel in Pembrokeshire’s crown."
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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