ruins of the lost Lustrine palace of Sola

Where is this?
The ruins of the lost Lustrine palace of Sola, deep in a valley gouged out by a glacier in ancient times. Geologically-recent rockfalls and treefalls have redirected streams through the centuries-abandoned city, with one such stream now flowing through the collapsed roof of the palace's grand antechamber. Additionally, the long years of neglect have enabled local vegetation to begin to reclaim the city. In another century's time, the entire city will be leveled to the foundations.
Why would your players want to travel here?
If nothing else, the treasures of the lost Lustrine civilization are a nice draw to get aspiring adventurers to make the climb up the Delurian mountains. In ages past, the people of Lustra were masters of artifice. Even their simple tools became imbued with a level of arcane magic not seen in recent years. As such, any number of arcanists, crafters, and archaeological researchers would pay good coin for any number of items that could be lifted from the moldering halls. Furthermore, only those who descend from the Lustrine royal line can open the doorways into the deepest reaches of the palace. In these innermost chambers, one can find the truth behind the city's abandonment.
What difficulties do they face getting here?
The foothills of the Delurian mountains are swarming with goblins and their "trained" pseudodragons. The mountains themselves can be treacherous at certain times of year, either during the winter snows or the spring thaws. The plants of the forest are every bit as hostile as the goblins - perhaps a lingering effect from whatever caused the city to fall to ruin. Furthermore, the city itself isn't half as dead as it appears, and the blackened corpses of those who have broken its silence in years past still wander its streets and prey upon those who follow them.
https://dungeonmasterblock.freeforums.net/thread/1642/dm-nastics-87-journey-destination