The interior of Camp Erdman's Assembly Hall was perhaps series' most versatile and oft-used on-location indoor set. Although false walls were erected and set dressing added, the hall's fireplace, white girder ceiling, and large, square tile flooring clearly expose its identity.
First a couple of pics from our tour. The first showcases the fireplace, the second I believe is the ocean side wall. (The ocean side exterior doubled as the DHARMA infirmary.)
Kate is confined to the New Otherton games room in season 3's The Man from Tallahassee and Left Behind.
Ben is later kept within the same room in season 4's The Economist.
We even get to see the games room back in DHARMA days during season 5's Lafleur. Of particular note is the addition of a classic 70s couch.
The Assembly Hall also became DHARMA's new recruit processing center, both for Ben and his Dad in The Man Behind the Curtain, as well as for Jack, Kate, and Hurley in Namasté. Also, the season 5 DVD special features show some behind-the-scenes action at this location.
The DHARMA classroom where Ben and Annie go to school in The Man Behind the Curtain is also shot at the Assembly Hall. The classroom makes a second appearance in Some Like it Hoth when drunk Roger Linus and Jack have a chat.
In He's Our You the hall stands in for DHARMA's cafeteria.
Even Pierre Chang has shot here! The scene where he attempts to film a DHARMA orientation video in Because You Left takes place right beside the fireplace.