The trails will be at 14 National Trust sites including Quarry Bank Mill and Speke Hall.
A father and son say the gaming craze is still going strong and their city has a community of fans.
Katherine Mayer says she fears for her safety after the cards were taken from her shop in Newark.
Small shops across the UK are being targeted by thieves stealing collectibles worth thousands of pounds.
Andrew Braund's collection sells for £32,800 at an auction in Woking on Thursday.
Andrew Braund finds his 20-year-old collection of Pokémon cards when he is clearing out his loft.
The Geek Experience at Trinity Market will return for its fourth year from 10:00 until 16:00 BST.
As the value soars, more and more people are stashing away cards in the hope of making a profit.
"This is no niche collecting field – it is a multi-billion-pound market," the auctioneers say.
