The Prague Huntik Hotel was where Sophie Casterwill, Lok Lambert and Dante Vale stayed prior to their starting the mission, The Golem of Prague. Due to an unnamed double agent within the Huntik Foundation, several Redcap Titans were hidden there to ambush them. It is also where they first met Zhalia Moon in the same episode when she used her Strix titans to help them S1E03.
The team regrouped here with Lucas Casterwill and his team, after learning the location of the Amulet of Void. Lucas then told the team about the story of the Betrayer. S2E31
Lucas, Lane and Dellix were still residing here when Lok Lambert summoned Quetzalcoatl, and activated the Blue Star. S2E38