The message when opening the Grand Exchange trapdoor says: This trapdoor leads to a small dwarven mine cart station. The mine cart will take you to Keldagrim. If you haven't visited Keldagrim, and attempt to use the trapdoor, you will get a message saying You must visit Keldagrim to use this shortcut. Before the release of the trapdoor, players had to travel through a cave northeast of Rellekka to reach Keldagrim, or use the Mine Cart system. Players can use quick travel method, that bypass the option to travel or not, by clicking the right mouse button on the trapdoor and click 'Quick-travel'. fi:Hidden trapdoor