Texy

Hi there, I'm pretty new to the forums, I'm sorry if this post is in the wrong spot. Recently I've been walking around the map filling up my pokedex and doing sidequests, but I can't seem to get back to Citae Arc-d'Astra (the place where you fight El with his Arceus/Ditto. Since in ep16 the grand stairway and the grand gate have been renovated, the normal way of going there does no longer exist. Has anybody found another way or is it cut off now? Thanks in advance, Texy