Maidalen is a valley, 1.2nmi long in a north–south direction, extending from Maiviken to Lewis Pass on Thatcher Peninsula, South Georgia. This feature was originally considered to be a part of Bore Valley but has since been determined to be a separate valley. It was named Maidalen (May valley) by the UK Antarctic Place-Names Committee in 1990 following in the Norwegian form an association with Maiviken.