The Small Heath (Coenonympha pamphilus) looks similar to the Meadow Brown (Maniola jurtina) and the Gatekeeper (Pyronia tithonus), but is distinguished by its much smaller size and the hairy backs of the wings.

1st photo: Speulderveld, Garderen, The Netherlands, 26 July 2016
2nd & 3rd photo: Near Stichtse Brug, Blaricum, The Netherlands, 27 August 2012
4th photo: Laarder Wasmeer, Hilversum, The Netherlands, 9 August 2014
5th photo: Air Force Base, Soesterberg, The Netherlands, 23 June 2019