A vane structure for a gas turbine engine. The vane structure includes a radially outer platform and a radially inner platform, and an airfoil having an outer wall extending radially between the outer platform and the inner platform. A cooling passage is defined within the outer wall and has a plurality of radially extending channels. An outer end turn structure is located at the outer platform to conduct cooling fluid in a chordal direction between at least two of the channels. The outer end turn structure includes an enlarged portion wherein the enlarged portion is defined by an enlarged dimension, in a direction transverse to the chordal direction, between the at least two channels.