The hide of Castelletto Merli is located at SKUA headquarters office, in Monferrato, surrounded by fruit trees and endemic plants which provide food all year 'round. The drinking water pool is frequented by many passerins like Blackcap, Common Redstart, Blackbird, Cirl Bunting, Melodious Warbler, Common Chiffchaff. But the stars of this hide are the Sparrowhawk, Green Woodpecker and Great Spotted Woodpecker tha show up very frequently to bathe and drink.