Climent purses his lips and reaches forward running his fingers along one of the carvings in the 'floor'. It comes away with red flecks on it. You're not sure, but you think it looks like dried blood. "To get us in? Unfortunately no, but... if you could come with me..." he walks over to the cliff edge and points downwards. Gazing down yourself you see what appears to be speck, slightly different in colour than the surrounding rocks "See that? I suspect that that is the remains of some poor soul, that whomever was here sacrificed to open this door. This may not be our way in, but it certainly does tell us something about those who first found the path.
Upon seeing Klyman examining the door itself he says Mr. Sylar, I suspect you are wasting your time. According to my research this is not a door as such, but rather an enchanted portal. It was crafted by the Eld during their dominion over humanity as a sort of 'back door' into the dungeon or sally port out of it should the need arise. It will not 'open' per say, but rather allow anyone who can activate it to teleport within... approaching closer he runs his fingers along the outline of several of the sigils and draws them to his nose, first smelling, and then briefly touching his tongue to a silvery substance that has rubbed off on them. Turning to face you he extends his hand so you can see what he has found. This is a rare substance called by several names. You may have heard of it as Liquid Moonsilver, Alchemists Silver, or Quicksilver. It has been traced all over the glyphs on the wall, many drams worth, likely costing a small fortune, while human blood was used to trace the symbols here he points at his feet... He pauses as though collecting his thoughts before picking up the larger of the two books he had been consulting and opening it to show you a particular page. It is covered in drawing of circles within circles and complex notations written beside them in what appears to be High Thulian.
"Now this is an old Celestial Almanac. In spite of their distrust of sorcery, the Thulians had among them several notable astrologers, and they were able to predict the movements of celestial bodies many years into the future. It was, and is seen as being a highly ordered approach to the pursuit of magic. My interest was piqued when I heard that the strange occurrences around Dwimmermount began just over two months ago as the timing was... somewhat unique. Now the Eld were true masters of astrology and drew much of their power from the celestial spheres, when they were not aligning themselves with demonic beings for power at least. This he says pointing at the page drawing is of a relatively rare celestial occurrence called the Triple Conjuncture which is when our world of Telluria and the moon Ioun are aligned with the Green Planet Kythirea and the Red Planet of Areon. It only occurs every fifty eight years, but if you look at this table here, you'll notice something very, very interesting... the last Conjuncture was exactly two months and three days ago. He looks up at you somewhat owlishly his eyes wide and excited.