Medal Great Britain Westminster Abbey
Hello Joseph -- You have a commemorative medallion, sometimes called a proof, with famous London tourist attractions. These are sold by merchants to UK visitors for a few US dollars or a few tens of US dollars. As far as I know, none are made of precious metal, although gold plating is an option (see the spiffy medallion in our secondary picture). Check eBay using a search on 'westminster abbey' to see representative items. Remember that eBay prices are only valid for items actually sold. Click on the 'sold listings' link first, then note the prices.
With no precious metal and with modern production dates, these pieces are worth very little on the secondary market. The medallion in our primary picture has been exposed to the elements and is worth less than $1 US dollar. 
If you have a pristine example in excellent condition, a coin dealer might pay a few dollars for it.
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Coin: 13843, Genre: Medals, Timeline: Modern
Created (yyyymm): 201302, Last review: 201501
Appearance: Normal round coin Metallic gray Metallic yellow Letters: Latin
Years: sort: 1990, filter: 1948 to 2050
Image: medal_westminster_abbey.jpg
Tags: escutcheon encircled dwelling shiled trees fort circal church rings galloping british crests katherdale part secvnd twice courthouse crest secvndae insignia centered brittish chevrons ben bridge clock shrine westminster cruciform tree cathedral third circling stallion mounted architectural arm second skyline encircles crossing horseman certer circel encircle shields riding england cabin ringed reins centers circumference skyscraper brittain encircling castel rein coats centre brittan elm ring hut three catholic tower cathederal cath rider two circles loop circumscribed britt prance equestres circumscibed maltese brit circuit chevron barn english coat benj britan crosses equestrian logo britian off abbey horse ride battlements arms cathedrale mountie circlet castle circle building offcenter casa britain creast residence crossed sheild castles benjamin prancing loops horses maltise mount horsehead circular criss incircled pony architecture crested towers buildings home house workhouse cross circled houses mosque horseback buildin shield center escucheon great offset shild structure parts
